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JN  preparing  this  catalogue  we 
have  endeavored  to  include 
information  which  will  en- 
able customers  to  intelligently 
select  the  lamp  best  suited  to 
particular  requirements.  **  The 
opening  section  is,  therefore, 
devoted  to  the  manufacture, 
selection  and  proper  use  of  lamps, 
and  we  believe  it  will  repay  care- 
ful perusal.  Descriptions  and 
illustrations  of  the  various  types 
of  our  lamps,  including  standard, 
special  and  miniature  lamps,  arc 
given  in  the  following  pages,  and 
the  appended  general  lamp  data 
should  prove  valuable. 

We  invite  correspondence  re- 
garding special  lamps  of  any  type, 
which  we  arc  prepared  to  manu- 
facture to  order. 

For  the  convenience  of  our 
patrons,  large  and  varied  stocks 
of  lamps  arc  carried  in  the  follow- 
ing cities: 

Lamp  Factory,  Harrison,  N.  J. 
Atlanta,  Ga.  Boston,  Mass. 
Chicago,  III.  Cincinnati,  O. 
Denver,  Col.  San  Francisco,CaI, 


Digitized  by  the  Internet  Archive 
in  2017  with  funding  from 
Columbia  University  Libraries 


https://archive.org/details/edisonincandesceOOgene 


EDISON 
INCANDESCENT 
^ LAMPS 

^ iV 


GENERAL  ELECTRIC  COMPANY 

Principal  Offices,  Schenectady,  N.  Y. 

Mjin  Lamp  Sales  Office*,  Harrison,  N.  J» 

FEB.  26,  1900  NUMBER  1028 


J 


THE  INCANDESCENT 
LAMP  IS  THE  VERY 
SOUL.  THE  ESSENCE 
OF  ELECTRIC  LIGHT- 
ING, AROUND  WHICH 
ALL  OTHER  DETAILS 
OF  CURRENT  PRO- 
DUCTION REVOLVE 
AS  SATELLITES  TO 
A CENTRAL  SUN.' 


STAIRWAY  IN  THE  CONGRESSIONAL  LIBRARY  AT  WASHINGTON,  D.  C 


THE  MANUFACTURE  OF 

INCANDESCENT  LAMPS 


LTIIOUGH  an  [^incandescent 
lamp  is  apparently  a very 
simple  device,  its  manufacture 
involves  many  complex  pro- 
cesses. In  addition  to  the 
mechanical  problems,  various 
chemical,  electrical,  and  physi- 
cal questions  must  be  solved 
in  its  construction.  In  no 
other  manufacturing  enter- 
]M'ise  is  success  so  deqrendent 
on  experience  combined  with 
careful,  systematic  inspection 
and  testing;  for  apparently  in- 
significant changes  in  methods 
produce  marked  results  and 
the  cause  of  defects  is  there- 
fore difficult  to  locate  and 
remedy. 

Many  jiersons  are  sur- 
pri.sed  when  told  that  fifty 
constructive  operations  and 
forty  separate  tests  and  m- 

A Tiffany  Candelabra  . r i i 

spcctions  arc  pciTormea  by 
the  (ieneral  Mlectric  Company  upon  every  lamp  to 
complete  it  for  the  market. 

To  jiroduce  an  incandescent  lamp,  and  sell  it  at 
our  present  low  price,  without  omitting  any  detail  of 


6 


GENERAL  ELECTRIC  COMPANY 


manufacture  or  tests,  is  an  achievement  rendered  pos- 
sible only  by  our  enormous  output  and  many  years  of 
experience.  The  bidison  lamp  represents  the  most 
extended  exjierience  and  the  largest  production,  and 
therefore  stands  unrivaled. 

Correct  and  uniform  rating  in  candle-power  by  ac- 
curate standards  has  always  been  the  distinguishing 

feature  of  the  Edison  lamiv 
CANDLE-POWER  RATING  ,,,,  ^ 

1 he  common  practice  of 

over-rating  lamps  or  of  shipping  lamps  varying  widely  in 

both  candle-power  and  watts  is  never  permitted  with 

Edison  lamps. 

The  eye  can  make  only  a vague  approximation  of  a 
lainji’s  candle-power,  and  a customer  not  proxdded  with 
a photometer  is  therefore  easily  deceived.  Unreliable 
manufacturers  sometimes  take  advantage  of  this  fact  to 


supply  lamps  o\'er-rated  in  candle-power  and  therefore 
in  economy.  A true  i6  candle-power  lamp  consuming 
50  watts  has  an  economy  of  3.1  watts  per  candle;  but  if 
it  be  a 13  candle-power  lamp  marked  16  candle-power, 
its  economy  is  really  3.8  watts  per  candle. 

Lack  of  uniformity  in  both  candle-power  and  watt 
ratings  of  lamps  is  an  evil  which  is  frequently  charac- 
teristic of  the  product  of  the  small  and  incompetent 
manufacturer.  \"ariation  in  candle-power  produces  disa- 

greeable  contrasts  in 

VARIATION  IN  CANDLE-POWER 

the  illumination,  and 
lack  of  uniformity  in  the  wattage  produces  irregular 
meter  bills — both  sources  of  dissatisfaction  to  customers. 

An  examination  of  lamps  on  the  market  emphasizes 
the  importance  of  purchasing  from  the  oldest  and  largest 
manufacturing  company  whose  reliability  as  to  uniform 
and  accurate  standards  and  ratings  is  established. 


7 


THE  GENERAL  ELECTRIC  COMPANY'S  INCANDESCENT  LAMP  FACTORY  AT  HARRISON, 
Capacity  Per  Day  60,000  Incandescent  Lamps— Annual  Production  15,000,000  Lamps. 


GENERAL  ELECTRIC  COMPANY 


While  the  low  prices  of  the  past  three  years  have 
compelled  many  lamp  manufacturers  to  economize  by 
abridging  processes  and  neglecting  vital  points,  the 
(ieneral  Iflectric  Company  has  imj)roved  its  methods 
and  machinerv,  given  lamps  more  detailed  attention 
than  ever,  and  is  now  producing  a lamp  far  surpassing 
in  cpiality  any  lamp  formerly  sold  at  double  the  price. 
The  immense  annual  production  of  fifteen  million  lamps 
makes  these  results  possible  and  also  permits  the  adop- 
tion of  new  improvements  and  the  establishment  of  a 
laboratory  for  e.xperimental  work  at  the  cost  of  only  a 
small  fraction  of  a cent  per  lamp  with  a large  produc- 
tion, but  at  a prohibitory  cost  to  the  average  lamp  factory 
producing  only  a few  hundred  thousand  lamps  per  year. 
Ifx'idently  a lamp  company  able  to  conduct  such  work 
on  the  most  e.xtensive  scale  can  offer  its  customers 
uniformity  of  product  and  e.xcellence  in  quality  other- 
wise unobtainable. 

Among  the  many  new  processes  which  have  tended 
to  improve  the  quality  of  Ifdison  lamps,  the  new  method 
of  exhaustion  is  undoubtedly  the  most  important. 
The  features  and  advantages  of  chemical  e.xhaustion 
are  now  well  known  and  require  no  further  comments. 
It  may  be  said,  however,  that  the  process  has  recently 
been  perfected  and  the  results  obtained  with  it  are 
outside  of  the  range  of  possibility  with  the  old  mechani- 
cal or  mercury  pumps. 

Attention  is  called  to  the  illustrations  of  the  new 
standard  form  of  bulb  recently  adopted.  The  interior 
volume  and  surface  of  the  bulb  have  been  increased  with- 
out adding  to  the  maximum  diameter,  and  the  heating 
and  tendency  to  blacken  are  thus  reduced.  The  bulbs  of 
all  lamps  are  molded  and  are  uniform  in  shape  and  size. 


9 


BALL-ROOM  OF  THE  HOTEL  WALDORF-ASTORIA,  NEW  YORK 


GENERAL  ELECTRIC  COMPANY 


Our  processes  of  manufacture  are  manifold,  careful, 
and  exact iipe,',  embodying  all  the  improvements  and 
every  detail  that  our  judgment  and  extensive  ex]ierience 
show  are  necessary  to  make  a finished  lamp  of  the  finest 
appearance  and  highest  cpiality  — considerations  always 
foremost  with  us.  I'he  results  are  as  they  should  he. 
the  Mdison  lamp  stands  today  absolutely  unequalled,  the 
standard  incandescent  lamp  of  the  world. 

W’e  were  the  first  manufacturers  of  lamps  and  have 
always  produced  more  than  the  combined  output  of  all 
the  other  factories  in  America.  W'e  have  by  constant, 
careful,  intelligent,  and  thorough  work,  steadily  increased 
the  commercial  possibilities  of  the  incandescent  lamp, 
building  up  the  market  for  it  and  supplying  for  )^ears  a 
clientage  of  the  largest  lamp  consumers  in  the  world 
with  the  most  perfect  incandescent  lamp  on  the  market. 
'I'he  lulison  lamp  of  today  is  farther  than  ever  in  ad- 
vance of  other  makes,  and  it  has  opportunities  to 
improve  at  a far  more  rapid  pace  than  is  possible  for 
any  other  lamp.  The  Tdison  lamp  with  its  eminent 
superiority  is,  therefore,  rapidly  leaving  all  competitors. 

Our  present  annual  production  of  over  fifteen  million 
lamps  enables  us  more  easily  to  produce  a lamp  which 
justifies  the  following  statement  made  several  years  ago 
by  the  largest  consumer  of  lamps  in  the  world: 

“Comparative  tests  of  ‘New  Type  Edison  Lamps’ 
with  those  of  other  makes,  both  Iuiroj)ean  and  Ameri- 
can, demonstrate  that  in  maintenance  of  candle-power, 
efificiency  and  average  life,  the  ‘New  Type  Edison  Lamp’ 
surpasses  them  all.” 


THE  SELECTION  OF  LAMPS 


X purchasing  lamps  the  average 
customer  considers  only  two 
points — the  first  cost  of  the  lamp 
and  the  time  it  will  last.  Two 
other  points  are,  however,  even 
more  important  and  should  not 
be  neglected.  One  is  the  initial 
economy  of  the  lamp,  or  the 
number  of  lamps  which  can  be 
supplied  per  horse-power.  Lamps 
are  classified  accordins;  to  voltacre, 
candle-power,  initial  economy,  and 
tN'pe  of  cap  or  base.  The  term 
initial  economy  is  used  to  denote 
the  amount  of  power  consumed 
by  the  lamp  at  starting  e.xpressed 
in  watts  per  candle,  as  for  example,  “3.5  watts  economy” 
means  that  the  lamp  requires  3.5  watts  for  each  candle- 
jiower  of  light  gi\  en,  or  that  a 16  candle-power  lamp  would 
require  56  watts.  High  economy  lamps  that  require  small 
power  per  candle  are  more  susceptible  to  variations  of 
pressure  and  have  shorter  lives  than  low  economy  lamps 
that  consume  relatively  more  power  per  candle. 

The  Ldison  lamp  is  furnished  in  three  different 
initial  economies: 

3. 1 watts  per  candle,  or  twelve  16  candle-power  lamps 
to  the  mechanical  horse-power. 

3.5  watts  i^er  candle,  or  ten  16  candle-power  lamj^s  to 
the  mechanical  horse-power. 

4 watts  i)er  candle,  or  eight  16  candle-power  lamps  to 
the  mechanical  horse-power. 


In  the  Hotel  S^ivoy 
New  York 


12 


GENERAL  ELECTRIC  COMPANY 


THE  LIFE  OF  A LAMP 


The  other  important  point  to  be  considered  is  the 
period  of  useful  life,  beyond  which  it  is  economical  to 
install  a new  lamp  even  though  the  old  one  be  still 
unbroken.  Mere  life  is  not  the  principal  feature  of  a 
lamp  nor  the  most  desirable. 

The  fact  that  one  lamp  outlasts 
another,  no  more  indicates  superiority  than  docs  the 
length  of  a ])lot  of  ground  determine  its  area.  A 
lamp  may  be  made  to  give  any  length  of  life  desired  and 
\'et  consume  so  much  current  as  to  make  it  cost  more  to 
burn  than  a lamp  gi\'ing  half  the  life  but  consuming  less 
power.  A lamp  may  also  have  long  life  and  yet  give  so 
low  an  average  of  candle-power  as  to  make  it  a very 
undesirable  and  worthless  lamp. 

The  features  of  first  importance  in  an  incandescent 
lamp  are,  therefore,  economy  (energy  consumed  for 
light  gi\'en ) and  maintoiance  of  candle-pozucr.  The 
point  to  be  observed  in  purchasing  lamps  is  therefore  to 
select  the  lamp  in  which  the  average  candle-jrower, 
energy  consumed  and  length  of  life  are  combined  to 
produce  the  best  and  most  economical  results, — that  is, 
to  irive  the  trreatest  amount  of  litrht  for  least  cost. 


It  is  a fact  demonstrated  by  impartial  tests  of 
scientific  institutions  and  by  the  practical  experience  of 
the  largest  electric  light  companies,  that  the  New  Type 
Edison  Lamp  e.xcels  all  others  in  the  most  efificient  com- 
bination of  these  desirable  qualities.  It  is  therefore 
the  most  economical  lamp  to  purchase  although  its  first 
cost  is  not  the  lowest. 

The  following  facts  determine  the  conditions  to 
which  each  type  of  lamp  is  best  adaiited. 

Lamps  of  an  economy  of  3.1  watts  per  candle  will 
give  satisfaction  only  where  the  regulation  of  voltage  at 


13 


GENERAL  ELECTRIC  COMPANY 


the  Station  is  the  best,  or,  in  other  words,  where  the 
voltage  at  all  times  is  practically  constant.  Such  regula- 
tion can  be  secured  only  by  constant  and  intelligent 
attention,  and  the  use  of  reliable  indicators  or  volt- 
meters. 


lUumination  of  the  U.  S.  Government  Building  at  the  Omaha  Exposition 

Lamps  of  an  economy  of  3.5  watts  ]ier  candle 
shoukl  he  used  where  the  regulation  is  fair,  that  is, 
where  the  ma.ximum  variation  does  not  e.xceed  4%. 

Lamps  of  an  economv  of  4 watts  per  candle  should 
he  ordered  in  every  case  where  the  ])lant  is  supposed 
to  he  self-regulating,  receixes  little  or  no  attention, 
and  has  no  reliable  pressure  indicator  or  voltmeter  in 
constant  use. 


14 


GENERAL  ELECTRIC  COMPANY 


Where  the  reg'ulation  of  Noltage  is  first-class,  it  is, 
of  course,  possible  to  obtain  almost  unlimited  average  life 
from  any  make  of  incandescent  lamp  of  low  economy. 
I’sing  lamps  of  such  prolonged  life  is,  however,  a decided 
mistake  and  is  uneconomical  in  every  way,  as  is  shown 
in  the  following  section  and  in  the  Appendix. 

We  in\  ite  correspondence  regarding  the  particular 
conditions  under  which  plants  are 

operated,  and  will  be  pleased  to  CORRESPONDENCE 
aeb  ise  as  to  what  economy  of  lamp  REGARDING 
will  best  suit  the  recpiirements.  LAMPS 

Whatever  economy  of  lamp  is 

selected,  no  one  thing  will  so  greatly  increase  the 
efficiency  of  the  plant  as  the  effort  to  maintain  constant 
voltage  at  the  lamps. 

The  economy  mentioned  above  is,  of  course,  initial 
econom\',  and,  like  candle-power,  is  nothing  more  than  a 
specification  for  lamps.  It  must  not  be  confounded,  as 
it  often  is,  with  the  average  economy  given  by  a lamp 
during  its  life.  The  latter  is  determined  by  the  candle- 
power  maintenance  and  is  a true  measure  of  lam[) 
cpialit}',  while  initial  economy  is  not. 


THE  PROPER  USE  OF  LAMPS 


LAMP  to  give 
satisfaction  must 
not  only  be  prop- 
erh'  made,  but  it 
must  also  be  prop- 
erl)- used.  A lamp 
of  the  highest 
cpialit)-  may  be  so 
misused  as  to  give 
only  a small  frac- 
tion of  its  rated 
light  capacity. 
I’roper  use,  pro- 
ducing a ma.xi- 
mum  of  light  at  a 
minimum  e.vpense 
recpiires: 

That  the  lamps  be  burned  at  marked  voltage; 

That  the  voltage^be  kept  constant; 

That  lamps  be  replaced  whenever  they  get  dim. 

The  last  requirement  is  not  considered  economical 
by  many  users  who  prize  lamps  that  have  long  life  and 
insist  on  using  them  as  long  as  they  will  burn.  Let  us 
see  by  an  e.xample  if  extremely  long  life  is  desirable. 

As  the  cost  of  current  varies  greatly,  we  will 
assume  an  average  cost  of  one-half  cent  per  lamp  hour. 
If  a rated  i6  candle-iiower  lamj),  burned  for  looo  hours, 
be  burned  an  additional  icoo  houns,  it  takes  practically 
the  same  current  during  the  last  period,  but  gives  an 
average  light  of  only  about  8 candles.  The  cost  of 

i6 


GENERAL  ELECTRIC  COMPANY 


current  for  the  2000  hours  is  $10.00.  A new  lamp  costs 
20  to  25  cents,  and  had  three  lamj^is,  with  a life  of  about 
700  hours  each,  been  used  during  the  entire  period,  the 
average  light  would  have  been  fully  doubled,  at  an 
added  e.xpense  of  not  more  than  50  cents  or  5%  of  cost 
of  current.  In  other  words,  by  adding  5%  to  operating 
e.xpenses  (representing  the  cost  of  the  two  renewal 
lamirs)  the  customer  would  add  100%  to  the  light  gi\  en. 
( )ne  new  lam])  gives  a light  equal  to  two  old  ones  at  half 
the  cost  of  current.  If  the  old  lamps  gave  light  enough, 
the  new  lamps  would  halve  the  number  of  lamps  in  use 
and  produce  the  same  light  with  half  the  current. 

It  is  im])ortant  to  note  that  the  above  example  is 
based  on  residts  obtained  with  the  highest  grade  of  lamps. 
W ith  an  inferior  quality  of  lamp  the  argument  against 
extremely  long  life  would  be  still  stronger  and  the  neces- 
sity of  frequent  renewals  of  lamps  much  greater. 

Thus,  from  an\'  jroint  of  view,  it  is  false  economy  to 
select  lamps  with  a sole  regard  for  long  life.  Lamps 
should  be  renewed  when  dim,  for  in  no  other  way  can 
light  be  jiroduced  economicallv. 

The  points  to  be  remembered  are  as  follows: 

Do  not  run  pressure  above  the  voItag:e  of  the  lamps* 
Increased  pressure  means  extra  power,  and  although  old 
lamps  may  thus  give  more  light  for  a while,  every  new 
lamp  that  does  not  break  from  excessive  pressure  will 
deteriorate  very  rapidly  and  give  greatly  diminished  light. 

Do  not  treat  incandescent  lamps  like  lamp  chimneys 
and  use  them  until  they  break.  They  should  be  renewed 
whenever  they  get  dim. 

d he  section  on  Life  and  Candle-jiower  in  the  Ap- 
pendix of  this  ])ami)hlet  gives  a complete  discussion  of 
this  subject 


A Column  in  the  Dining  Room  of  the  Hotel  Netherland,  New  York 


I 


GENERAL  NOTE 

LAMP  BASES 
All  lamps  (not  miniature,'  sup- 
plied by  the  General  Electric 
Company  arc  fitted  with  Stand- 
ard Edison  Screw  Bases,  or  any 
of  the  following  bases  : Westing- 
house,  Thomson-Houston,  United 
States,  Brush-Swan,  Edi-Swan, 
Hawkeyc,  Mather,  Perkins,  or 
Schaeffer. 

FROSTING  jZ  .jJt 

AND  COLORING 
Any  lamp  can  be  furnished 
frosted,  or  in  almost  any  color, 
either  dipped  or  in  natural  glass. 


STANDARD  50  VOLT 
INCANDESCENT 
LAMPS 


general  electric  company 


4,  6,  8,  AND  10  CANDLE-POWER 
50  VOLT  LAMPS 

For  service  requiring  only  a moderate 
quantity  of  light,  we  furnish  4,  6,  8, 
and  10  candle-power  lamps.  Owing  to 
the  e.xtreme  fineness  of  the  filaments, 
these  lamps  are  more  sensitix  e to  variation 
in  voltage  than  standard  16  candle-power 
lamps  of  the  same  economv.  h'or  this 
reason,  to  secure  uniform  average  life, 
lanqis  of  low  candle-power  should  be 
ordered  of  lower  economv  than  the 
standard  16  candle-power  lamps  to  operate 
under  the  same  conditions.  The  filaments 
being  comparatively  short  and  stiff  are 
best  adapted  to  the  looj)  form. 

SPECIFICATIONS 


A Column  in  the  Ifulb -Molded-Peai'-shaped.  Size  as 

P.trIor  of  the  Hotel  S.ivoy  j,-,  illustration. 

New  York  ]-'ilament — Loop  in  45  to  60  volt  lamps ; 

spiral  in  60  to  90  volt  lamps. 

\h)ltages~  45  to  90. 

Econom\- — 4 candle-i)ower  lanqis,  5 watts  per 
candle;  6 candle-jxiwer  lamps,  3.6  and  4.5  watts  per 
candle;  8 and  10  candle-ixiwer  lamps,  3.1,  3.6  and  4 watts 
])er  candle. 

The  10  candle-power  4 watt  lanq)  is  furnished  in  the 
.same  size  bulb  as  the  standard  16  candle-power  50  volt 


V 


4,  6,  8 and  10  Candle-power 
50  Volt  Lamps 


general  electric  company 


i6,  20,  AND  24  CANDLE-POWER 
50  VOLT  LAMPS 


0\\’  voltage  lamps,  b\  reason  of  their  heavier  fila- 


■I— ' ments,  give  slightlv  better  results  than  can  he 
obtained  with  high  voltage  lamps.  This  superioritv 
permits  of  the  use  of  3.1  watt  lamps  in  place  of  lamps  of 
3.5  watts  or  lower  economies.  W'e  ha\  e for  some  years 
supplied  a large  number  of  alternating  current  stations 
with  50  to  55  volt,  3.1  watt  lamps.  The  service  they 
give  is  e.xcellent.  The  use  of  such  high  economy  lamps, 
besides  saving  power,  keeps  the  ax  erage  life  from  being 
too  prolonged.  I'he  life  of  low  voltage  3.5  and  4 watt 
lamps  outlasts  their  usefulness,  and  therefore  the  higher 
econoni}'  3.1  watt  lamps  are  desirable. 

W’e  use  the  looj)  form  of  filament  because  it  is  the 
best  permissible  with  a filament  necessarilv  too  short 
and  stiff  for  the  spiral  form. 


SPECIFICATIONS 


Bull) — Molded-Bear-shai)ed.  Size  as  in  illustration 
(e.\cej)t  the  20  candle-power,  4 watts  per  candle,  and  the 
24  candle-power,  3.6  and  4 watts  per  candle  lamps  which 
are  in  larger  bulbs). 

Filament  Loo])  in  45  to  60  volt  lamps;  spiral  in  60 
to  90  volt  lamps. 

X’oltages — 45  to  90. 

Fconomy--i6,  20,  and  24  candle-power  lamps,  3.1, 
3.5  and  4 watts  per  candle. 


16,  20  and  24  CaniIc-powc»- 
50  Volt  Lamps 


GENERAL  ELECTRIC  COMPANY 


32  CANDLE-POWER  50  VOLT  LAMP 


Wl'L  have  adopted  the 
voltage  lamps  in  ])refi 
we  have  tried  and  discarc 
filament,  to  give  the  best 
results  in  maintained 
candle-power  and  free- 
dom from  blackening, 
requires  a length  too 
short  to  wind  in  a well 
formed  spiral.  The 
spiral  filament,  owing  to 
the  weight  of  the  coil 
at  the  end,  tends  to 
droop  more  than  the 
loop.  Altogether  our 
e.xtensive  e.xperience 
with  low  voltage  lamps 
shows  that  the  looj)  form 
of  filament  makes  a 
better  lamp. 

SPECIFICATIONS 


loop  filament  for  our  low 
erence  to  the  spiral,  which 
led.  The  proper  size  of 


If  ul  b — M ol  ded  - 
Pear-shaped.  Size  as  in 
illustration. 

In  the  Ball-room  of  the  Hotel 

h ilament  — Loop  in  Waidorf- Astoria 

45  to  6o  volt  lamps: 
si)iral  in  6o  to  90  volt  lamps. 

X’oltages — 45  to  90. 

I'iconomv — 3.1.  3.6  and  4 watts  per  candle. 


26 


32  Candle-power  50  Volt  Lamp 


GENERAL  ELECTRIC  COMPANY 


50  CANDLE-POWER  50  VOLT  LAMP 


APK()lMCk  ])r<)j)()rtion  should  always  be  presL'rvcd 
between  the  size  of  the  bulb  and  the  candle-power 
of  an  incandescent  lamp.  Too  large  a bulb  is  unneces- 
sarily heavy,  occupies 
much  space  and  is 
hulk\'  in  ajipearance, 
while  too  small  a bulb 
causes  undue  beating 
and  blackening. 

The  illustration  of 
our  standard  50  can- 
dle-]5ower  low  voltage 
lamp  clearl)'  shows  the 
harmony  of  ])roi:K)r- 
tion  m candle-power 
and  size  of  bulb.  'I'be 
lulison  lamp,  as  is 
well  known  In'  all 
users,  also  maintains  a 
full  ratio  of  light  given 
to  power  consumed,  to 
a greater  degree  than 
any  other  lam]L  ( )ur 
50  candle-power  lamps 
accurate  and  perfect 


In  a Corridor  of  the  Hotel  Waldorf-Astoria 


can  be  depended 
coiistruction. 


SPECIFICATIONS 

Hull)  Molded-l’ear-sbaped.  Size  as  in  illustration. 
I'dlament  Loop. 

X'oltages — 45  to  90. 

I’icononiN' — 3.1  and  3.6  watts  per  candle. 


50  Candlc-pDwcr  50  Volt  Lamp 


GENERAL  ELECTRIC  COMPANY 


100  AND  150  CANDLE-POWER  50  VOLT  LAMPS 


11  ]C  mechanical  structure  of  the  heavy  filaments  in 


A hi^h  candle-power  lamps  requires  special  attention. 
W'e  have  found  that  the  jj^reatest  strength  and  rigidity 
are  secured  bv  the  use  of  the  double  loop  as  shown  in 
the  illustration  on  the  folded  page.  These  loops  are 
connected  in  multiple  and  burn  as  two  separate  carbons. 
The  chances  of  failure  are  thus  reduced  one-half,  for 
should  one  filament  break  the  other  remains  and  the  lamp 
will  burn  at  half  candle-power.  As  great  dejiendence  is 
placed  on  every  high  candle-power  lamp,  reliability  is  of 
marked  importance.  The  value  of  our  careful  and  c.xact 
processes  is  realized  in  this  type  of  lam]). 

Si)ecial  attention  is  called  to  the  heavy  currents 
carried  by  these  high  candle-power  lamps  and  the  conse- 
quent imixirtance  of  having  a large  and  certain  area  of 
contact  between  base  of  lamp  and  socket.  For  these 
lamps  6 to  9 amj)eres  at  50  volts  are  required,  and  on 
this  account  they  should  be  ordered  with  bases  to  fit 
Keyless  Socket  for  High  Candle-power  Lamj)s.  (Cat. 
Xo.  8319).  These  sockets  are  sj)ecially  designed  to  carry 
large  currents,  and  smaller  .standard  sockets  in  general 
use  are  not  reliable  for  this  })urpose.  These  high  candle- 
])ower  lam])s  are  ])referably  used  in  keyless  sockets,  but 
in  any  case  the  current  should  be  turned  off  and  on  at 
the  switch  and  not  at  the  socket. 


SPECIFICATIONS 


Hull) — Arolded-Pear-sha])ed.  Size  as  in  illustration, 
h'ilament  Double  loop,  the  two  loo])s  in  multiple. 
\h)ltages-  45  to  90. 

Economy  -100  candle-power  lain]),  3.1  and  3.6  watts 
l)er  candle;  150  candle-])ower  lam]),  3.1  watts  ])er  candle. 

Hased  with  High  Candle-])ower  Hase  to  fit  .Socket, 
Cat.  X'o.  8319,  or  with  any  standard  bases. 


30 


A Column  m the 

Dining  Room  of  the  Hotel  Majestic 
New  York 


i 

I 


100  lO  125  VOLT 
INCANDESCENT 
LAMPS 


GENERAL  ELECTRIC  COMPANY 


4,  6,  8 AND  10  CANDLE-POWER 
100  VOLT  LAMPS 

T1 1 ]-2  use  of  8 and  lO  candle-power  lamps  has  yreatly  in- 
creased m recent  years,  especially  amoiye;  residences. 

( )win“'  to  the  extreme  fineness  ol  their  filaments,  these 
lamps  have  not  the  stability  and  endurance  of  standard 
i6  candle-power  lamjis,  and  their  manufacture  involves 
j^'reat  difficulties.  Helie\ii\L;',  howex'cr,  that  such  lamps 
will  always  be  in  large  demand,  we  have,  through  con- 
centrated efforts,  matle  marked  improxements,  and  are 
now  able  to  offer  an  8 or  lO  candle-iiower  lamp  approach- 
ing in  quality  our  standard  i6  candle-power  lamp. 

h or  general  serx  ice,  where  regulation  is  not  perfect, 
nohighereconomy  than  3.5  watts  per  candle  should  be  used. 

Electric  signs,  hall  and  closet  lighting,  rec|uiring 
small  lighting  units,  have  producetl  a demand  for  4 and 
6 candlc'-power  lamj^s.  To  give  such  lamps  equal  sta- 
bility with  lamps  of  higher  candle-iiower,  they  are  made 
to  consume  Irom  4 to  5 watts  per  candle. 

SPECIFICATIONS 

Bulb-  Volded-Bear-.shaiied.  Size  as  in  illustrations, 
h'ilament— 4 candle-ptiwer  lamp.  Spiral,  specially  for 
sign  work. 

I'ilament— 6,  8 and  10  candle-power  lamps.  Oval, 
A nchored. 

X'oltages— 90  to  123. 

Economy — 4 candle-iiower  lamp,  5 watts  per  candle; 
6 candle-power  lamp,  3.6  and  4.3  watts  per  candle;  8 and 
I o candle-power  lanqis,  3 c S-f*  4 watts  iier  candle. 

4'he  10  candle-power  4 watt  lamp  has  the  same  size 
bulb  as  the  standard  16  candle-power  lamp. 


4 Candle-power  JOO  Volt  Lamp 


6,  8 and  10  Candle-power  100  Volt  Lamp 


33 


GENERAL  ELECTRIC  COMPANY 


16  CANDLE-POWER  100  VOLT  LAMP 

The  1 6 candle-power  high  voltage  lamp  is  the  stand- 
ard of  comparison  which  distinguishes  the  high  grade 
manufacturer  from  the  incompetent.  The  difficulties  met 
in  making  a perfect  50  \ olt  lamp  are  multiplied  when  the 
100  volt  lamp  is  attempted.  The  increased  voltage 
acting  upon  a finer  filament  results  in  rapid  deterioration 
and  loss  of  candle-power,  unless  its  construction  has 
been  given  careful  attention  bv  e.xperienced  workmen. 
The  average  manufacturer  is,  therefore,  unable  to 
produce  a high  loltage  lamji  of  higher  efficiency  than  3.5 
to  5 watts  per  candle.  The  successful  production  by  us 
of  a commercial  3.  i watt,  higb  voltage  lamp,  has  been 
largely  instrumental  in  bringing  incandescent  lighting  to 
its  present  advanced  stage. 

The  standard  New  Type  fulison  Lamp  here  illus- 
trated is  today  the  most  e.xtensivelv  used  lamp  in  the 
world  and  iqion  it  has  been  concentrated  the  greatest 
amount  of  skill,  time  and  attention. 

All  its  numerous  good  points  cannot  be  shown  in  an 
illustration.  Clean  white  light,  uniform  and  highly  sus- 
tained brilliancy,  and  good  average  life,  are  among  the 
most  notable  superior  cjualities  which  can  be  appreciated 
onlv  by  using  the  lamp.  The  carbon  filament  is  an- 
chored securely  in  position,  ami  thus  prevented  from 
vibrating  or  touching  the  glass.  The  filament  is  shaped 
to  fit  the  bulb  so  as  to  form  a bright  sphere  instead  of 
two  lines  of  light. 

SPECIFICATIONS 

bulb - Alolded-l’ear-shaped.  .Size  as  in  illustration, 
excepting  the  20  c.p.,  4 w.p.c.,  and  the  24  c.p.,  3.5  w.p.c. 
and  4 w.p.c.  which  are  in  larger  bulbs. 

I'dlament  ( )\  al,  Anchored.  \'oltages--90  to  125. 
Economv  -16,  20  and  24  candle-power  lamps,  3.1, 
3.5  and  4 watts  j’ler  candle. 


34 


16  Candle-power  100  Volt  Lamp 


GENERAL  ELECTRIC  COMPANY 

32  CANDLE-POWER  100  VOLT  LAMP 

The  beauty  of  form  and  brilliancy  of  the  oval  fila- 
ment are  strikingly  illustrated  in  our  higher  candle- 
power  lamps.  The  oval  filament  produces  a sphere  of 

light  e.xactly  filling 
the  bulb  and  its 
m a n y advantages 
enumerated  in  the 
description  of  the  i6 
candle-power  lamp 
are  here  accentu- 
ate d.  O u r n e w 
chemical  e.xhaustion 
process  is  of  special 
advantage  in  the  pro- 
duction of  32  candle- 
power  lamps.  It 
overcomes  man}'  of 
the  special  difificul- 
ties  in  the  e.xhaustion 
of  high  candle-power 
lamps  — blackening 
is  reduced,  mainte- 
nance of  candle- 
power  is  increased  and  the  quality  of  the  average  lamp  is 
materially  improved. 

SPECIFICATIONS 

Bulb — Molded-Bear-shaped.  Size  as  in  illustration, 
excepting  the  4 w.p.c.  lamp  which  is  in  a larger  bulb, 
b'ilament — Oval,  Anchored. 

X’oltages — 90  to  125. 

ICconomy — 3.1.  3.6  and  4 watts  per  candle. 


Electrolier  in  Hotel  Savoy,  New  York  City 


36 


32  Candle-power  100  Volt  Lamp 


37 


GENERAL  ELECTRIC  COMPANY 


50  CANDLE-POWER  100  VOLT  LAMP 

An  anchor  is  of  special  value  in  retaining  in  form 
and  position  the  heavy  filament  required  in  a 
50  candle-power  lamp.  The  compact  shape  of  the  oval 
avoids  the  necessity  of  using  a large  and  bulky  bulb. 


Our  new  exhaustion  process  produces  50  candle- 
jiower  lamps  in  which  blackening  is  reduced,  maintenance 
of  candle-power  increased  and  weak  spots  in  filaments 
avoided.  The  construction  of  our  50  candle-power  lamp 
is  accurate  and  thorough — features  that  are  especially 
desirable  where  reliance  is  jdaced  on  single  lamps  in 
service. 

SPECIFICATIONS 

Hulb —Molded -I’ear-shajK'd.  Size  as  m illustration. 

h'ilament — Oval,  Anchored. 

X’oltages — 90  to  125. 

Economy — 3.1  and  3.6  watts  per  candle. 

3S 


50  CandIc-pDwcr  100  Volt  Lamp 


GENERAL  ELECTRIC  COMPANY 


100  AND  150  CANDLE-POWER 
100  VOLT  LAMPS 

Reliability  is  a feature  of  prime  importance  in 
high  candle-power  lamixs.  When  dependence  is 
placed  on  a single  lamp,  its  failure  from  any  cause  is 
more  serious  than  the  failure  of  one  of  many  lamps  of 
lower  candle-jiower.  Our  exact  processes  and  indi\  idual 
treatment  secure  perfection  in  every  lamp.  The  loo  and 
1 50  candle-power  lamp  is  shown  in  the 
illustration  on  the  folded  page.  Lor 
mechanical  reasons  we  have  found  the 
double  loop  the  most  desirable  form  of 
filament  for  these  lam|is.  The  two  loops 
being  arranged  in  series,  each  loop  is  only 
half  the  length  neces.sary  with  one  continuous  filament, 
and  has  many  times  the  strength  and  rigidity.  These 
lamps  should  be  ordered  with  base  to  fit  Keyless  Socket 
for  High  Candle-power  Lamps.  ( Cat.  No.  8319.)  This 
.socket  is  specially  designed  to  carry  large  currents,  and 
smaller  standard  sockets  in  general  use  are  not  reliable 
for  this  purpose.  It  is  recommended  that  high  candle- 
power  lamps  be  used  in  keyless  sockets,  or  in  any  case, 
that  the  current  be  turned  off  and  on  at  the  switch. 

SPECIFICATIONS 

Bulb — Molded- Pear-shaped.  Size  as  in  illustration, 
h'llament  Double  loop,  the  two  loops  in  series. 
X’oltages — 90  to  125. 

Economy — 100  candle-jiower  lamp,  3.1  and  3.6  watts 
jier  candle;  150  candle  power  lamp,  3.1  watts  per  candle. 


DESIRABLE 

FORM 

OF 

FILAMENT 


■to 


An  Oxley  & Enos  Company 
Lighting  Fixture 


GENERAL  ELECTRIC  COMPANY 


THE  STREET  RAILWAY  LAMP 

An  unanchored  rtlanient,  to  withstand  the  shock  and 
vibration  of  street  car  serx'ice,  has  to  be  so  short 
and  stiff  that  the  light  is  limited  to  a very  small  area. 
The  efficiency  and  maintained  brilliancy  of  the  lamp  is 
thus  reduced,  as  well  as  the  general  illumination  of  the 
car.  The  position  of  the  anchor  is  also  an  important 
consideration.  Anchoring  the  lower  end  of  the  filament 
to  the  inside  of  the  bulb  is  objectionable,  as  it  holds  the 
filament  too  rigidly  and  the  effect  of  a shock  or  jar  is  to 
break  either  the  filament  or  the  anchor.  E.xcessive 
rigidity  cannot  be  overcome  by  resting  the  filament 
loosely  in  the  anchor,  since  vibration  of  the  filament 
against  the  anchor  will  cause  it  to  wear  away.  With 
a metal  anchor  firmly  connected  to  the  stem  or  inside 
part  of  the  lamp,  as  in  the  Edison  oval  filament,  shown 
in  the  accompanying  illustration,  the  ideal  arrangement 
is  secured.  The  filament  is  held  so  as  to  check  vibration 
rather  than  to  entirely  prevent  it.  Ereedom  of  vibra- 
tion within  proper  limits  is,  therefore,  allowed  and  the 
filament  is  not  strained  or  weakened.  With  the  anchor 
m the  position  shown,  the  whole  filament  vibrates 
together  and  there  is  practically  no  danger  of  the 
branches  interlocking  and  short-circuiting,  as  would  be 
the  case  if  one  branch  of  the  spiral  were  anchored 
rigidly  to  the  side  of  the  lamp,  and  the  other  branch 
free  to  vibrate  and  strike  it. 

Another  necessary  consideration  in  the  case  of 
Railway  Lamps  is  that  they  should  have  uniform  cur- 
rent capacity  since  they  are  ojK'rated  in  series.  Our 
Railway  Lamps  are  made  in  three  different  classes,  viz.: 
for  500  volt  circuits,  for  550  volt  circuits  and  for  600  volt 


GENERAL  ELECTRIC  COMPANY 


circuits.  In  each  class,  lamps  are  selected  of  a given 
amperage  to  within  .01  ampere.  Thus  carefully  tested 
for  candle-power  and  current  these  lamps  are  suited 


e.xactly  to  the  requirements  of  street  railway  service  and 
give  uniform  light  and  life.  Street  Railway  Lamps  of 
33  candle-power  or  other  candle-powers  are  furnished 
to  order. 

SPECIFICATIONS 

Bulb — Molded-Bear-shaped.  Size  as  in  illustration, 
h'ilament — Oval,  Anchored. 

Ifconom}' — 4 watts  ]ier  candle.  l‘'urnished  for 
operating  five  in  series  on  circuits  of  a total  of  500 
\'olts,  550  volts  or  600  volts. 


42 


The  Street  Railway  Lamp 


43 


SPECIAL 

INCANDESCENT 

LAMPS 


GENERAL  ELECTRIC  COMPANY 


200  TO  250  VOLT  LAMP 


E furnished  lamps  for  200  and  250  volt  circuits  on 


” special  order  for  several  years  before  the  general 
public  knew  that  sucb  a lamp  was  practicable. 

Their  successful  use  has  increased  the  annual  sales  of 
these  lamps  to  more  than  350,000. 

A perfect  vacuum  is  of  the  greatest  importance  with 
these  high  voltage  lamps,  for  unless  all  the  residual  gases 
are  thoroughlv  removed  from  the  bulb  the  lamps  are  liable 
to  e.xplode  at  the  high  voltage.  If  an  e.xplosion,  blowing  the 
lamp  into  fragments  and  causing  serious  short-circuits,does 
not  occur  in  a badly  exhausted  lamp,  the  inside  connections 
may  melt.  Our  new  process  of  exhaustion  is,  therefore,  of 
special  value  in  the  production  of  these  lamps.  By  this 
method,  individual  exhaustion  insures  a perfect  vacuum  in 
every  lamp  and  reduces  the  danger  of  e.xplosion  or 
failure  to  a minimum. 

Owing  to  the  increased  strain  to  which  the  carbtms 
or  filaments  are  subjected  by  the  high  voltage,  these 
lamps  are  uncommercial  except  in  the  lower  economies. 
The  economy  of  our  regular  product  is  4 watts  per  candle, 
and  in  its  average  life  and  maintenance  of  candle-power, 
is  somewhat  better  than  our  standard  100  to  125  volt  3.1 
watt  lamp. 

The  illustration  shows  our  latest  type  of  200  to  250 
volt  lamp.  The  length  of  filament  necessary  in  this  type 
of  lamp  is  most  advantageously  arranged  in  a double 
oval  which  is  firmly  held  in  position  by  t7vo  anchors. 
Such  an  arrangement  is  much  neater  than  the 
method  of  anchoring  to  the  inside  of  the  bulb,  and 
it  avoids  shadows.  An  anchor  from  the  lower  end  of 
the  filament  to  the  inside  of  the  bulb  is  useless,  as  the 

46 


GENERAL  ELECTRIC  COMPANY 


anchor  breaks  off  with  a slight  shock  and  the  wcii;ht 
of  it  destroys  the  filament.  The  ICdison  filament  is  so 
anchored  as 
to  alio  w 
some  \ibra- 
tionandthns 
relieve  the 
strain  on  the 
filament,  bnt 
the  vibra- 
tions are 
checked  so 
as  not  to  ex- 
ceed proper 
limits. These 
lamps  a r e 
made  in  8, 

10,  1 6,  20, 

24,  32  and 
50  candle- 
power. 

SPECIFICA- 
TIONS 


Bulb— 

M 0 1 d e d - 
Pear-shaped. 

Size  as  in  il- 
lust  rat  ion. 

Filament  — 
Donbleoval, 

Double  an- 
chored. 

\’oltao-es — 

200  to  250. 

ICcononn' — 4 watts  per 


candle. 


GENERAL  ELECTRIC  COMPANY 


ROUND  BULB  LAMPS 


For  window  or  other  decorations  and  for  all  installa- 
tions where  a short  bulb  is  desirable,  we  offer  our 
Round  Bidb  Lamps.  The  bulbs  are  2^"  in  diameter  and 
make  a very  neat  compact  t)  pe 
of  lamp.  The  oval  form  of 
anchored  filament  pro\'ides  the 
best  arrangement  for  the  long 
filament  of  high  voltage  lamps 
in  small  round  bulbs.  In  low 
voltage  lam]is  the  shorter  and 
stiffer  filament  is  well  adapted 
to  the  spiral  and  loop  forms. 
The  round  bulb  lamps  are 
frequently  used  in  street  railway 
service,  in  headlights  and  else- 
where. The)'  can  be  obtained 
specially  selected  for  amperes 
when  desired  for  railway  service. 


SPECIFICATIONS 


Bulb  — l\Iolded-Spherical-2|-" 
in  diameter. 

Filament,  too  volts  and  over — (')val.  Anchored. 

Filament,  50  to  60  volts — Spiral.  \h)ltagcs — 45  to  125. 

Flconomy,  8,  10  and  16  candle-power  lamps — 3.5 
and  4 watts  per  candle. 

Lamps  of  4 and  6 candle-power  in  this  tyjie  can  be 
furnished  if  desired,  also  32  and  50  candle-power  in 
larger  bulbs. 


48 


Round  Bulb  1 00  Volt  Lamp 


Round  Bulb  50  to  60  Volt  Lamp 


49 


GENERAL  ELECTRIC  COMPANY 


TUBULAR  LAMPS 

TLU^ULAR  or  “Bunghole” 

Lamps  are  useful  in  con- 
fined or  narrow  places.  The}’ 
were  originall}’  made  for  examin- 
ing the  interior  of  casks  and 
barrels,  the  lamps  being  inserted 
through  the  bunghole.  These 
lamps  are  also  frequently  used 
on  candelabra  and  resemble 
lighted  candles.  They  are  also 
effective  for  show  case  illumina- 
tion as  they  can  be  concealed 
inside  the  case  underneath  the 
moulding  strips.  With  the  tub- 
ular form  of  bulb,  the  loop  fila- 
ment anchored  at  the  lower  end  to  j^revent  sagging,  is 
most  suitable. 


SPECIFICATIONS 

Bulb — Molded.  The  illustration  shows  the  lOO 
volt  lamp  full  size.  The  50  volt  lamp  is  one-half  inch 
shorter  than  the  100  volt  lamp. 

Filament — Loop,  Anchored. 

\’oltages — 45  to  125. 

Fconomy,  8 and  10  candle-power  lamps — 4 watts  per 
candle. 

Fconomy,  16  candle-power  lamps — 3.1  watts  per 
candle. 

Lamps  of  32  c.p.  in  this  type  can  be  furnished  if 
desired,  but  will  be  made  with  larger  bulbs. 


50 


Tubular  Lamp 


51 


GENERAL  ELECTRIC  COMPANY 


STEREOPTICON  LAMPS 

TO  meet  a large  and  constantly  increasing  demand, 
we  supply  a specially  designed  lamp  for  stereopti- 
cons.  A comiDact  filament  is  here  essential  so  that  the 
light  shall  be  radiated  as  nearly  as  possible  from  one 
point.  As  these  lamps  are  required  only  in  the  higher 
candle-powers,  the  filament  is  necessaril}'  heavy  and 
must  not  be  too  closely  bent.  The  conical  spiral  fila- 
ment of  our  lamp  meets  these  conditions  most  satis- 
factorily. 

The  illustration  shows  the  50  candle-power  stereop- 
ticon  lamp  full  size.  W’e  also  manufacture  lower  and 
higher  candle-powers  to  special  order. 

SPECIFICATIONS 

Bulb — Molded-Round. 
h'ilament  — Conical  spiral. 

Voltages  — 45  to  125. 

Economy — 4 watts  per  candle. 


52 


53 


Stercopticon  Lamp 


GENERAL  ELECTRIC  COMPANY 


THE  EDISON  NIGHT  LAMP 


N objection  to  the  incandescent  light  has  always 


TTl  been  that  it  could  not  be  turned  down  or  dimmed. 
This  objection  has  been  overcome  in  the  Edison  Night 
Lamp.  A simple  movement  of  the  milled  screw 
provided  on  this  lamp  changes  the  candle-power  from 
si.xteen  to  one.  The  device  is  economical  as  well  as 
simple  since  the  current  consumed  is  reduced  with  the 
candle-power.  This  lamp  can  be  furnished  without  the 
screw,  if  a permanent  low  candle-power  lamp  is  desired. 
The  bulbs  are  always  frosted. 

The  Night  Lamp  is  particular!}'  adapted  for  use  in 
hospitals,  nurseries,  bed-chambers,  halls  and  closets. 


SPECIFICATIONS 


Bulb — Molded-Pear-shaped.  Size  as  in  illustration. 
Filament — Oval,  Anchored. 

Voltages — 45  to  125. 


54 


55 


The  Edison  Night  Lamp 


GENERAL  ELECTRIC  COMPANY 


RESISTANCE  LAMP 

Banks  of  lamps  for  resistance  are  in  quite  general 
use  and  are  ver\'  satisfactor\'  for  moderate  currents. 
We  ha\-e  f(jr  years  had  a large  demand  for  specially 
made  resistance  lamps,  of  the  type  shown  in  the  illus- 
tration. Resistance  lamps  are  furnished  in  tubular  bulbs, 
in  order  that  the\-  can  be  packed  closel}'  and  thus 
minimize  space.  The  filaments  are  loops  connected  in 
series  to  give  the  required  resistance.  Lamps  of  this  type 
can  be  furnished  of  any  desired  resistance  up  to  looo 
ohms  cold,  and  for  currents  up  to  fi\’e  amperes,  the 
power  consumed  per  lamp  not  to  e.vceed  loo  watts. 
Resistance  lamps  of  higher  power  consumption  can  be 
made  in  larger  bulbs  on  special  order.  In  ordering  state 
resistance  and  the  current  in  amperes  at  which  this 
resistance  is  desired. 

SPECIFICATIONS 

Bulb — AIolded-Tubular.  Size  as  in  illustration, 
h'ilament  — Loop.  Resistance — As  stated  above. 


56 


Resistance  Lamp 


For  Miniature  Lamps 
and  Appliances  and  any  Special  Lamps 
not  Described  in  this  Catalogue,  Address 
Edison  Decorative  and  Miniature  Lamp  Dept,. 
General  Electric  Company, 

Harrison,  N.  J. 


GENERAL  ELECTRIC  COMPANY 


CANDELABRA  AND  DECORATIVE  LAMPS 

1 1 1C  practical 
ajiplication  of 
C a n d e 1 a b r a 
Lamps  in  dec- 
orative interior 
lighting'  has  be- 
come so  general 
and  so  well  un- 
derstood that 
any  special  re- 
marks in  the 
sense  of  ex- 
ploitation are 
nnnecessary. 

The  Scries 
Candelabra 
Lamps  which 
were  intro- 
duced by  ns  a 
few  )'ears  ago 
have  constant- 
Iv  grown  in  public  favor,  and  are  now  in  extensive  use, 
chiefl\'  for  decorative  lighting  in  residences,  hotels  and 
other  places  for  which  they  are  eminently  suitable.  The 
favorable  reception  that  this  form  of  lighting  has  met, 
has  led  to  a demand  for  lamps  of  the  same  general  stvles 
and  sizes  capable  of  being  used  in  multiple,  instead  of  in 
series,  on  circuits  of  from  lOO  to  120  volts. 

Anticipating  such  a demand,  we  produced  several 
st\'les  of  multiple  burning  Camlelabra  Lamps,  which  arc 
shown  in  the  following  pages.  W’e  have  found  them  to 
be  a product  that  has  met  with  instant  favor  and,  in  con- 

61 


In  the  Parlor  of  the  Hotel  Majestic 


GENERAL  ELECTRIC  COMPANY 


sequence  of  their  many  points  of  excellence,  the  demand 
for  them  has  rapidl)’  grown. 

d'he  Special  Series  Lamps  have  also  retained  their 

great  popularity 
for  all  kinds  of 
tem])orary  and 
permanent  deco- 
rati\e  and  elec- 
tric sign  work.  In 
this  branch  we 
have  also  added  a 
multiple  burning 
lamp  to  meet  a 
demand  for  such 
a t\  j)e  of  lamp,  to 
be  used  more  es- 
pecially in  electric 
sign  work.  This 
lamp  has  filled 
many  require- 
ments for  that 
special  use  that 
could  not  be  met  by  the  series  lamps.  All  of  these 
lamps,  however,  series  and  multiple,  have  their  jiroper 
sphere  of  utility,  according  to  the  circumstances  under 
which  they  are  to  be  used. 

It  is  proper  to  call  special  attention  also  to  our 
Sockets  and  Receptacles.  Many  improvements  have 
been  made  in  them,  not  only  with  regard  to  their  useful- 
ness and  to  the  coin  enience  of  handling,  but  with  a view 
to  their  ajqiearance  and  increased  safety  from  a fire 
underwriter  s standpoint.  It  will  be  found  from  a careful 
e.xamination  of  the  sockets  and  receptacles  listed  in  the  fol- 
lowing pages,  that  we  have  so  devised  them  as  to  provide 
for  all  contingencies  that  could  be  reasonably  anticipated. 


62 


GENERAL  ELECTRIC  COMPANY 


REGARDING  SERIES  LAMPS 

T1 1 1C  lamps  shown  on  jia^es  64,  68  and  69  are 
made  esjieciallv  for  series  burning  on  electric  light- 
ing circuits. 

Particular  attention  is  called  to  the  following  general 
remarks  on  these  lam])s. 

If  these  reinarks  are  care- 
fully read  before  ordering  or 
using  an\'  of  these  series  lam]Ls, 
purchasers  will  save  themselves 
and  us  considerable  trouble,  ex- 
pense and  delay. 

The  most  important  point 
in  burning  lamps  in  series  is 
that  the  amperes  of  each  of  the 
lamps  in  any  one  series  should 
be  the  same  within  three  one- 
hundredths  of  an  amjrere. 

The  voltage  of  the  lamps 
may  var\-,  but  the  sum  of  the 
voltages  in  any  series  must 
ecpial  the  voltage  of  the  cir- 
cuits within  three  volts. 

In  selecting  lamps  for  am- 
one  series,  use  only  lamps  of 
aiiproximately  the  same  amperes  and  see  that  the  sum 
of  their  voltages  equals  the  voltage  of  the  circuit. 

In  replacing  a lamp  which  has  burnetl  out  m any 
scries,  use  only  a lamp  of  the  same  voltage  and  amperes 
as  the  one  broken. 

In  ordering  series  lamps  to  replace  those  burned  out, 
give  both  voltage  and  amperes  of  those  in  use,  also 
voltage  of  circuit. 


<>3 


SERIES  CANDELABRA  LAMPS 


GENERAL  ELECTRIC  COMPANY 


SERIES  CANDELABRA  LAMPS 


Sl-HvIES  candelabra  lamps  are  made  in  five  different 
styles,  A,  B,  C,  D and  E,  and  are  furnished,  when 
specified,  to  be  used  two,  three  or  four  in  series  on 
electric  lighting  circuits  of  lOO  to  120  volts,  and  two 
in  series  or  in  multiple  on  circuits  of  50  to  60  volts. 

Style  A is  always  a 10  candle-power  lamp. 

Styles  B,  C,  D and  E differ  from  each  other  only  in 
the  shape  of  the  bulbs,  but  they  all  ^ , 

differ  from  the  style  A lamp  in  that 
the  candle-power  of  the  lamp  varies 
according  to  the  number  used  in 
series.  On  100  to  120  volt  circuits, 
two  lamps  in  series  give  8 candle- 
power  each — three  in  series,  5 candle- 
power  each  — four  in  series,  4 
candle-power  each.  If  burned  in 
multiple  on  circuits  of  50  to  60  volts 
each  lamp  will  give  about  8 candle- 
power. 

All  colored  candelabra  lamps 
are  made  of  natural  glass,  e.xcept 
amber-colored,  which  are  dipi^ed. 

Lbrless  otherwise  ordered  the  Style  D 
frosted,  as  a better  effect  is  thereby  obtained, 
made  in  colors. 

A 7)iperes  and  volts  are  etched  on  each  lanip. 

Note  directions  for  ordering,  page  63. 

The  above  lamps  will  fit  Candelabra 


lamp  is 
It  is  not 


and  Receptacles  Nos.  i,  2,  3, 
and  74. 


Sockets 
6 and  7,  pages  72,  73 


65 


GENERAL  ELECTRIC  COMPANY 


MULTIPLE 

CANDELABRA  AND  SIGN  LAMPS 

MLU/riPLl'^  canclekibra  lamps,  St)'les  A,  15,  D and 
E ha\'e  been  especially  designed  for  burning  in 
multiple  on  circuits  of  lOO  to  120  volts.  In  ordering 
these  lamps  the  voltage  of  the  eircuit  should  be  specified 
and  the  lamps  be  designated  as  Multiple  Candelabra 
Lamps,  Styles  A,  B,  U or  E to  dis- 
tinguish them  from  the  Series  Cande- 
labra Lamps  of  the  same  styles. 

The  multiple  sign  lamp.  Style  F, 
was  especially  designed  to  fill  a de- 
mand for  small  lamps  to  burn  in 
multiple  in  illuminated  signs  ha\ing 
letters  from  ten  inches  to  two  feet  in 
height.  It  has  attained  a great  popu- 
larity for  use  in  this  connection,  as 
well  as  in  many  other  lines  on  account 
of  its  size,  beauty,  candle-power,  and 
economy  in  the  use  of  current.  It  is 
an  8 candle-power  lamp,  is  furnished  for  use  in  multiple 
on  circuits  of  100  to  120  volts,  and  takes  a current  of 
about  .28  ampere.  In  ordering  these  lamps,  the  voltage 
of  the  circuit  should  be  specified. 

All  colored  multiple  candelabra  and  sign  lamps  are 
made  of  natural  glass,  except  amber-colored,  which  are 
dipped. 

Lbiless  otherwise  ordered  the  Style  1)  lamp  is  frosted, 
as  a better  effect  is  thereby  obtained.  It  is  not  made  in 
colors.  Note  directions  for  ordering,  page  63. 

The  above  lamps  will  fit  Candelabra  Sockets  and 
Receptacles  Nos.  i,  2,  3,  6 and  7,  pages  72,  73  and  74. 


67 


GENERAL  ELECTRIC  COMPANY 


SPECIAL  SERIES  LAMPS 


8 Candle-power 
2 in  series  on  100- 
J20  volts.  In  multi- 
ple on  50-60  volts. 
Current  required  for 
each  series  will  aver- 
age about  .50  amp. 


5 Candle-power 
4 in  scries  on  JOO- 
120  volts.  2 in 
scries  on  50-60  volts. 
Current  required  for 
each  series  will  aver- 
age about  .55  amp. 


The  following  lamps  are  called  “Special  Series” 
Lamps  to  distinguish  them  from  Candelabra  and 
Batter)-  Lamps.  We  furnish  these  in  four  different  candle- 
powers  for  burning  m series  on  electric  lighting  circuits 
of  too  to  120  volts,  or  on  circuits  of  50  to  60  volts. 

6S 


GENERAL  ELECTRIC  COMPANY 


The  8 candle-power  lamp  is  used  for  decorative  pur- 
poses where  large  units  of  light,  but  few  in  number,  are 
desired.  In  illuminations  coveringf 
a large  area  this  lamp  can  be  used 
advantageous- 
ly. It  is  also 
used  in  multi- 
ple for  illumi- 
nated signs  on 


3 Candle-power 
8 in  scries  on  I OO-1 20  volts. 
4 in  scries  on  50-60  volts. 
Current  required  for  each 
scries  will  average  about  I 
amp. 


I Candle-power 
8 in  scries  on  I00-I20  volts. 
4 in  scries  on  50-60  volts. 
Current  required  for  each 
scries  will  average  about  .33 
amp. 


Special  Scries 
Theatrical  Lamp 


50  to  60  volt  circuits.  The  5 candle-power  lamp  is  also 
used  for  decorative  purposes  where  large  units  of  light, 
but  few  in  number,  are  desired,  and  it  can  be  used  advan- 
tageously in  illuminations  covering  a large  area.  It  is 
used  quite  extensively  in  decorative  sign  work  where  the 
effect  to  be  obtained  is  not  based  upon  the  employment 
of  large  units  of  lights  but  upon  the  special  design  or  the 
number  of  lamps  used. 

The  3 candle-power  lamp  is  used  for  decorati\  e pur- 
poses in  cases  where  plenty  of  current  is  obtainable.  Wc 
do  not  recommend  its  use  where  lamps  are  to  be  placed 


69 


GENERAL  ELECTRIC  COMPANY 


close  together,  as  in  sign  work  and  many  cases  of  floral 
decorations,  because  it  becomes  quite  hot  in  continual  use. 

The  I candle-power  lamp  is  that  which  we  most 
strongl)'  recommend  for  sign  and  decorative  work  where 
lamps  are  to  be  placed  close  together.  It  gives  a good 
light,  generates  very  little  heat,  and  each  series  requires 
only  about  one-third  of  an  ampere  of  current.  It  is 
therefore,  the  best  small  lamp  for  series  work,  whether 
for  interior  signs,  'among  flowers,  or  otherwise. 

The  theatrical  lamp  is  made  to  give  i candle-power, 
burning  i6  in  series  on  lOO  to  120  volt  circuits  or  8 in 
series  on  50  to  60  volt  circuits.  It  is  e.xtensively  used  for 
theatrical  purposes,  for  decorating  dancers  and  produc- 
ing special  effects.  Each  series  takes  about  one-half 
ampere  of  current.  This  lamp  is  carried  in  stock  as 
an  unbased  (or  wire)  lamp,  and  will  be  so  shipped  unless 
otherwise  ordered.  If  desired  it  will  be  furnished  fitted 
with  miniature  screw  base  to  fit  No.  4 Receptacle  or 
No.  5 Socket. 

All  colored  series  lamps  are  made  of  natural  glass, 
except  amber-colored,  which  are  dipped. 

A7npcres  and  volts  are  etched  on  the  S candle-power 
and  5 candle-power  lamps. 

Note  directions  for  ordering,  page  63. 

The  8 candle-power  and  the  5 candle-power  lamps 
will  fit  Candelabra  Sockets  and  Receptacles  Nos.  i,  2,  3, 
6 and  7,  pages  72,  73  and  74. 

The  3 candle-power  and  the  i candle-power  lamps 
will  fit  Miniature  Lamp  Receptacle  and  Socket  Nos.  4 
and  5,  page  72. 


70 


Candelabra  in  the  Hotel  Savoy 
New  York 


GENERAL  ELECTRIC  COMPANY 


No.  2 Receptacle  No.  4 Receptacle 


No.  6 Receptacle 


No.  3 Socket  No.  5 Socket 


72 


GENERAL  ELECTRIC  COMPANY 


RECEPTACLES  AND  SOCKETS 

FOR  MINIATURE  LAMPS 


No.  I is  known  as  the  Standard  Round  Candelabra 
Receptacle.  It  is  made  of  porcelain  and  is  especially 
despyned  for  use  on  h.xtures  fitted 
with  i;iass  candles,  d'he  receptacle 
screws  into  a central  supporting 
tube,  anil  the  candles,  when  in  place, 
completely  cover  both  supporting 
tube  and  receptacle.  It  will  re- 
ceive lamps  having  candelabra 
screw  base. 

No.  2 is  the  Standard  h'lat 
Base  Candelabra  Recejitacle.  It  is 
made  of  porcelain  and  will  receive 
lamps  shown  on  pages  64,  66  and  68. 
No.  3 is  the  Candelabra  Socket. 
It  is  made  of  brass,  with  porcelain  insulating  parts,  and 
will  recei^■e  lamps  shown  on  pages  64,  66  and  68. 

No.  4 is  the  Standard  Round  Miniature  Lamp 
Receptacle.  It  is  made  of  porcelain  and  will  receive  the 
3 and  I candle-power  lamps  fitted  with  miniature  screw 
base — page  69. 

No.  5 is  the  Standard  Socket  for  use  with  Miniature 
Lamps.  It  is  made  of  brass  with  porcelain  insulating 
parts,  and  will  receive  the  3 and  i candle-power  lamps 
fitted  with  miniature  screw  base — page  69. 

No.  6 is  a Special  Receptacle  for  sign  work,  and  is 
supplied  with  litharge  lining  for  use  in  outdoor  work  if 
specially  ordered.  The  No.  6 has  been  designed  for 
strength  and  compactness  and  is  very  extensively  used  for 


No,  I Receptacle 


73 


GENERAL  ELECTRIC  COMPANY 


sign  work  of  all  kinds.  It  is  made  of  porcelain  and  will 
receive  lamps  shown  on  pages  64,  66  and  68. 

No.  7 is  a Donble-pole  Fused  Receptacle  which  has 
been  designed  to  meet  the  recpiirements  of  certain 
climatic  conditions  demanding  the  use  of  fuses  in  con- 
nection with  the  receptacle  itself.  It  is  also  particularly 
suitable  for  many  classes  of  inside  work  necessitating  the 
use  of  an  ornamental  receptacle.  This  receptacle  is  made 
of  porcelain  and  has  a remo\’able  cap  or  cover  concealing 
both  connections  and  fuses,  yet  permitting  ready  access 
thereto.  It  will  recei\'e  lamps  shown  on  pages  64,  66, 
and  68. 


No.  7 Receptacle 


GENERAL  ELECTRIC  COMPANY 


SHADES  FOR  MINIATURE  LAMPS 


A 


The  star  shade  here  illustrated  is  made  especially  for 
certain  classes  of  decorati\  e woik,  and  presents  a very 
handsome  and  striking  effect  when  the  lamps  are  lighted. 

The  type  of  Shade-holder  Attachment  shown  below 
is  furnished  for  use  with  Sockets  Nos.  3 and  5.  It  is 
made  of  brass  and  may  be  readily  attached.  As  these 
attachments  are  not  interchangeable  for  Sockets  Nos.  3 
and  5,  customers  should  be  careful  in  ordering  to  state 
with  which  socket  the  attachment  is  intended  to  be  used. 


GENERAL  ELECTRIC  COMPANY 


The  shades  for  miniature  lamps  illustrated  below  are 
intended  for  use  with  lamps  shown  on  pages  69  and  78. 
Special  shades  for  larger  miniature  lamps  can  be 
supplied  on  order.  They  are  furnished  in  the  following 
colors:  Red,  White,  Blue  and  Green  with  edgings  of 
different  colors. 


76 


GENERAL  ELECTRIC  COMPANY 


BATTERY  LAMPS 


The  lamjis  shown  on  the  following  j^ages  are  made 
especially  for  use  with  batteries  and  are  not  adapted 


They  are  made 
of  8,  10,  i6,  20 
and  24  candle-power,  and  from  8 to  45  volts,  with  an 
economy  of  from  2.5  to  4 watts  per  candle. 


for  series  work. 
They  should  not 
under  any  cir- 
cumstances be 
used  for  series 
lighting. 

Battery  lamps 
as  shown  in  the 
accompanying 
illustration  are 
e.xtensively  used 
for  railway -car- 
riage lighting 
andforotherpur- 
poses  in  connec- 
tion with  storage 
battery  plants. 
They  are  made 
up  in  standard 
bulbs  of  about 
the  size  shown 
in  the  cut,  and 
can  be  furnished 
to  fit  all  stand- 
ard sockets. 


GENERAL  ELECTRIC  COMPANY 


BATTERY  LAMPS-*  Continued) 

The  batter}'  lamps  here  illustrated  are  described  in 
the  accompanying  table.  Wc'  make  no  lamps  taking 
less  than  J volts. 


DESCRIPTION. 

CANDLE- 

POWER. 

ELECTRO- 

MOTIVE 

FORCE. 

VOLTS. 

CURRENT 

REQUIRED. 

APPROX. 

AM  PERES. 

Standard  Battery  Lamp 

1 

T 

i 

8 to  0 

4 to  () 

1.00  to  .00 

1.40  to  .00 

2 

4 to  7 

2.00  to  1.10 

8 

5 to  7 

2..j0  to  1.75 

• 

4 

7 to  !l 

2..50  to  1.75 

() 

!)  to  12 

2.75  to  2.00 

GENERAL  ELECTRIC  COMPANY 


BATTERY  LAMPS  • Continued) 

The  battery  lamps  here  illustrated  are  described  in 
the  aceompan}'ing  table.  11  £■  niakc  no  lanips  taking  less 
than  J volts. 


Dental  Special  Dental  Special  Dental  Surgical 

Side  Seal  Side  Seal  Bottom  Seal  Lamp 


DESCRIPTION. 

CANDLE- 

POWER. 

ELECTRO- 

MOTIVE 

FORCE. 

VOLTS. 

CURRENT 
RE<)U1  RED. 

A PPKOX. 

A M P E R ES. 

Dental  Lamp,  Side  Seal 

1 

H to  5 

l.u  to  .(1 

Special  Dental,  Side  .Seal 

1 

T 

75  to  5 

1 .(1  to  .(i 

Special  Dental,  llottom  Seal 

.1 

.'5  to  0 

1.0  to  .0 

Surgical  Lamp 

T 

75  to  0 

1.0  to  .0 

Pea  Lamp 

T 

7f  to  5 

1.0  to  .0 

i C.P. 


special 


The  telephone  lamps  here  shown 
are  specially  made  for  use  on  tele- 
phone switchboards.  They  are 
desig'iied  to  take  a very  small 
quantity  of  current.  The  volts  and 
current  required  are  as  follows; 

One-fourth  c.p.,  lo  or  12  volts,  .14 
ampere. 

One-half  c.p.,  20  or  24  volts,  .14 
ampere. 

These  lamps  are  fitted  with  a 
“spring  jack”  base  for  switchboard 


i c.p. 


service. 


79 


GENERAL  ELECTRIC  COMPANY 


BATTERY  LAMPS-  < Continued) 

The  bicycle  lavip  here  shown  is  the  form  and  type 
of  lamp  most  generally  used  with  storage  or  primary 
battery  for  bicycle 
headlights,  etc.  It 
is  of  high  economy, 
gi\  ing  about  J of  ^ 
candle-power  at  4 
volts  and  .50  ampere. 

We  also  supply  a sim- 
ilar lamp  of  about  J Candic  Fiat  Lamp 

Bicydc  Lamp  candlo-powcr  at  4 volts 
and  .25  ampere.  These  lam])s  are 
always  furnished  with  miniature 
screw  base  to  fit  our  No.  4 Recep- 
tacle or  No.  5 Socket,  unless 
otherwise  ordered. 

The  Diificr's  lamp  is  a flat 
lamp  of  one  candle-power  arranged 
with  loops  at  the  top  and  bottom,  l Candle  Miner's  Lamp 
in  order  that  it  can  be  hooked 
upon  springs  in  the  miner’s  lantern 
and  so  held  steady.  This  lamp  re- 
quires about  3.5  to  5.5  volts,  and 
.90  to  1 .40  amperes. 

The  electromotive  force  re- 
quired for  the  flat  lamps  is  3 to  5 
volts  for  the  f candle-power  and  7 
to  9.5  volts  for  the  4 candle-power. 

The  current  required  is  .80  to  1.35, 
and  1.25  to  2 amperes,  respectively. 


4 Candic  Flat  Lamp 


80 


GENERAL  ELECTRIC  COMPANY 


BATTERY  LAMPS  (Continued) 


The  electromotixe  force  required  for  the  sphetical 
lamp  is  7 to  9.5  volts.  'I'he  current  required  is  1.25 
to  2 amperes. 

The  kineto- 
scope  lamp  is  that 
originally  adopt- 
ed for  use  in  the 
lulison  Kineto- 
scope,  and  it  is 
still  used  there- 
with all  over  the 
world.  As  will 

4 Candk  Spherical  Lamp.  Pj.  fj-Qj.,.,  ^he 

illustration,  the  filament  is  in  spiral 
form,  thus  providing  for  concentration 
of  the  light  in  one  spot.  This  lamj) 
is  always  furnished  with  miniature 

iAinctoscopc  Lamp 

screw  base,  to  fit  No.  4 Recejxtacle  or  4 Candic-power 
No.  5 Socket, unless  otherwise  ordered.  ® 


Both  of  the  microscope  lamps  here  shown  ha\e  been 
designed  to  meet  a growing  demand  for  a small  l^attery 
lamp  easily  fitted  in  various  surgical  instruments  and 
holders.  They  both  gix'e  '/z  candle-power  from  3 to  5 
volts,  with  an  amperage  of  from  .6  to  i. 


GENERAL  ELECTRIC  COMPANY 


BATTERY  LAMPS — (Continued) 


# , The  6 candle-power  lamp  shown  here 

K has  been  especially  designed  for  use  with 

Automobiles.  It  is  made  for  6 
candle-power  at  22  and  at  14  volts. 
It  can  be  supplied  based  with  either 
candelabra  base  (as  in  cut)  to  fit 
Nos.  I,  2,  3,  6 or  7 Receptacles, 
or  with  miniature  base  to  fit  No.  4 
or  No.  5 Receptacles. 

A special  wire  lamp  guard  is 
supplied  for  this  lamp,  where  there  is  danger  of  breakage. 
This  guard  is  designed  for  connection  to  No.  3 or  No.  5 

Receptacles,  and  both  guard 
and  receptacle  are  nickel 
plated,  presenting  a hand- 
some appearance. 

The  electromotive  force 
required  is  from  30  to  38 
volts,  and  the 
current  from 
1.75  to  2.50 
amperes. 


Automobile  Lamp 


Stick-pin  Lamp  Watch-charm  Lamp 


We  have  not  heretofore  listed  the  stick-pin  and 
ivatch-chann  lamps,  ha\’mg  usuall)'  sujoi^lied  them  only 
on  special  order.  The  demand  for  these  ornaments  has 


GENERAL  ELECTRIC  COMPANY 


them  in  stock 


BATTERY  LAMPS  ( Concluded) 

of  late  become  so  general  that  we  have  decided  to  cariA' 
regularl)'.  The  lamps  are  similar  in 
appearance  to  an  ordinar\'  incan- 
descent lamp,  but  they  are  only 
dummies  and  cannot  be  lighted. 
\ The  examination  lamp  for 

storage  batteries  shown  m the 
accompanying  illustration  has 
been  designed  and  is  being  suc- 
cessfully used  for  making  e.xami- 
nations  of  the  plates  of  large  ac- 
cumulators. The  bulb  of  the 
lamp  is  fiat  and  its  diameter  is  as 
shown  in  the  illustration.  At- 
tached to  the  bulb  is  a glass 
stem  about  40  inches  long, 
making  the  total  length  of  the 
lamp  appro.ximately  42  inches. 

The  two  leading  wires  are 
insulated  from  each  other  and 
extend  through  the  glass  stem. 

Ordinarily  the  leading  wires 
are  attached  to  a flexible  cord, 
which  is  connected  with  five  of 
the  accumulator  cells.  If  de- 
sired, these  lamps  will  be  fur- 
nished with  our  candelabra  screw 
base,  or  with  regular  standard 
bases,  so  that  they  may  be  con- 
veniently connected  by  means  of  our  No.  3 Socket  with 
flexible  cord.  These  lamps  are  made  to  give  4 candle- 
power  each  at  10  volts,  or  6 candle-power  at  20  volts. 


OF  INFORMATION  ON 
INCANDESCENT 
,)  LAMPS 


GENERAL  ELECTRIC  COMPANY 


LIFE  AND  CANDLE-POWER  OF  LAMPS 

IXCE  the  prime  function  of  a 
lamp  is  to  give  light,  the  best  lamp 
is  one  that  gu’es  maximum  light 
at  minimum  cost.  Simple  as  this 
axiom  is,  few  users  of  lamps  fol- 
low it  out  in  practice.  Lamps 
are  repeatedly  selected  for  long 
life  irrespective  of  good,  uniform 
candle-power.  Lamps  are  con- 
tinued in  use  long  after  their  candle- 
power  has  seriously  diminished. 

An  e.xamination  of  the  charac 
teristics  of  an  incandescent  lamp 
will  give  a clear  understanding  of 
the  principles  apphdng  to  their 
selection  and  use.  A theoretically  perfect  lamp  would 
maintain  its  normal  candle-power  indefinitely,  or  until 
the  lamp  was  broken.  In  practice  the  deterioration  of 
the  lamp  filament  causes  a steady  loss  of  candle-power. 

The  drop  in  candle-power  is  a characteristic  of  an 
incandescent  lamp  always  to  be  borne  in  mind.  The 
relati\'e  drop  or  loss  of  candle-power,  other  things  being 
equal,  determines  the  comparative  value  of  different 
lamps.  We  ma)’  have  a lamp  that  loses  50%  in  candle- 
power  inside  of  200  hours  on  a 3.  i watt  economy  basis. 
This  type  is  almost  invariabl)'  furnished  by  the  inexperi- 
enced manufacturer,  and  there  are  many  such  lamps  in 
the  market.  Considered  from  the  standpoint  of  life  only, 
such  lamps  maybe  excellent,  because tbeir  filaments  deteri- 
orate to  such  a degree  that  it  is  practically  impossible  to 
supply  enough  current  to  brighten  them  up  to  the 


86 


GENERAL  ELECTRIC  COMPANY 


RENEWAL  OF  LAMPS 


breaking'  point,  but  no  discerning  station  manager  would 
want  such  dim  lamps  even  with  unlimited  life.  .\s  in  the 
selection  of  incandescent  lamps  so  in  their  use  — the 
exclusive  consideration  of  life  leads  to  poor  results.  Loss 
of  candle-power  in  a lamj)  sooner  or  later  makes  it  uneco- 
nomical to  continue  in  use. 

There  is  no  lamp  {less  than  p suatts pereandle)yet  made 
tvhich  is  eeonomieal  to  burn  over  1000  hours,  and  in  the 
great  majority  of  eases  the  limit  is  under  6oo  hours. 

An  incandescent  lamp  is  nothing  more  than  a trans- 
former, receiving  current  and  transforming  it  into  light. 
After  a certain  time  this  trans- 
former may  lose  50  % in  effi- 
ciency, taking  practically  the  same  current,  but  giving 
only  about  one-half  the  light.  A boiler  or  an  engine 
suffering  such  loss  in  efficiency  would  be  promptly 
repaired  or  replaced.  The  renewal  of  incandescent  lamps 
is  even  more  important.  The  old  lamps  jeopardize  the 
customer’s  trade  with  their  poor  and  expensive  light.  A 
customer  cares  little  how  efficiently  a station  is  operated, 
but  is  much  concerned  about  the  C|ualit\'  of  light  furnished. 
At  the  present  price  of  lamps,  doubling  the  number  of 
lamp  renewals  adds  little  to  cost  of  operation,  while  it 
increases  the  lighting  efficiency  40%  to  50%.  These 
principles  are  carefully  obser\'ed  by  many  of  the  large 
lighting  companies,  and  a force  of  men  or  boys  is 
employed  to  weed  out  and  replace  all  dim  lamps.  Some 
such  means  of  keeping  the  average  life  below  600  hours 
should  be  adopted  by  every  lighting  comiiany  that  has 
any  regard  for  the  economical  jiroduction  of  light  or  the 
satisfaction  of  their  customers. 

A simple  method  is  to  fix  the  average  life  at  600 
hours  or  less  and  then  determine  from  the  station  record 


ILLUMINATION  OF  OMAHA  EXPOSITION  GROUNDS-FINE  ARTS  BUILDING 


GENERAL  ELECTRIC  COMPANY 


how  many  lamps  should  be  renewed  each  month  to  keep 
the  averai;'e  life  within  this  limit.  The  required  number 
of  lamps  should  be  renewed  each  month. 

If,  for  e.xample,  a station  decides  on  an  axerage  life 
not  to  exceed  600  hours  and  the  station  records  show  that 
on  the  average  60,000  lamp  hours  of  current  are  sujrplied 

monthlx’,  then  it  would  be  necessary  to  renew 
100  lamjis  a month. 

Some  stations  attempt  to  correct  the  dimness  of  old 
lamps  by  raising  the  voltage,  but  this  is  bad  practice, 
since  the  increased  jiressure  damages  every  new  lamp 
placed  in  circuit. 

THE  IMPORTANCE  OF  GOOD  REGULATION 

PROPER  SELECTION  AND  USE  OF  TRANSFORMERS 

Poor  regulation  of  voltage  probably  results  in  more 
trouble  with  customers  than  any  other  fault  in  electric 
lighting  service. 

Some  central  station  managers  act  on  the  theory 
that  so  long  as  the  life  of  the  lamp  is  .satisfactory,  an 
increase  of  voltage,  either  temporary  or  permanent,  will 
increase  the  average  light.  The  fact  is  that  when  lamps 
are  burned  abox’e  their  normal  rating  the  average  candle- 
power  of  all  the  lamps  on  the  circuit  is  decreased  after 
several  hundred  hours  of  service,  and  if  the  station  is  on 
a meter  basis,  it  increases  the  amount  of  the  customers’ 
bills. 

Pixcessive  voltage  is  thus  a double  error — it  decreases 
the  total  light  of  the  lamps,  and  increases  the  power 
consumed.  The  loss  of  light  displeases  the  customers 
and  discredits  the  service.  If  light  is  sold  by  meter,  the 
increased  power  consumption  dissatisfies  the  customers; 
if  light  is  sold  by  contract,  the  additional  power  is  a dead 


89 


GENERAL  ELECTRIC  COMPANY 


loss  to  the  station.  If  increased  light  is  needed,  20 
candle-power  lamps  should  be  installed  instead  of  raising 
the  pressure.  Their  first  cost  is  the  same  as  16  candle- 
power  lamps;  they  take  but  little  more  current  than  16 
candle-power  lamps  operated  at  high  voltage  and  give 
greater  a\erage.lighL-  - _ 

Increased  pressure  also  decreases  the  commercial 
life  of  the  lamp,  and  this  decrease  is  at  a far  more  rapid 
rate  than  the  increase  of  ju'cssure  as  shown  in  the  follow- 
ing table.  This  table  shows  the  decrease  in  life  of 
standard  3.1  and  3.5  watt  lamps  due  to  increase  of 
normal  voltage. 


EFFECTS  OF  CHANGE  IN  VOLTAGE 

STANDARD  3.1  WATT  LAMP 


VOLTAGE 

I*ER  CENT.  01 

NORMAL. 

CANDLE- 

POWER 

PER  CHN 1.  OF 

NORMAL. 

WATTS  PER 

CAN  DLK- 

POWER. 

LIFE 

PER  CENT.  OF 

NORMAL. 

DETERIORA- 

TION 

PER  CENT.  OF 

NORM  ^ I.. 

V m _ 

. — ■ 54 

4 {\'A 

1141  _j 

— - 11 

111 

5S 

4.41 

710 

14 

‘l-i 

02 

4.21 

7)00 

IS 

!i;i 

00 

4.04 

4:45 

2:4 

ii-i  — 

70..) 

8.S1I 

:44.) 

211 

;i:)  “ 

— 7 •')  ^ 

;!.74 

-77) 

oT) 

!l(i 

so 

o. ’)!» 

220 

45 

!IT 

s.") 

:!.40 

1711 

50 

!IS 

00 

140 

Oil 

!lll 

^ 10(1- — 

101 

ilo 

1 ( M ) 

;!.2i 

;!.io 

;!.oo 

121 

100 

S2 

S4 

loo 

100 

122 

10-i 

1 12 

2.111 

OS 

147 

lo;: 

IIS 

2.S2 

7)() 

1711 

lof 

124 

2.7:4 

40 

217 

10.') 

LIO 

2.04 

;4s 

20;4 

loii  LIT 

1 

— 32 

:4i:4 

90 


GENERAL  ELECTRIC  COMPANY 


EFFECTS  OF  CHANGE  IN  VOLTAGE 

STANDARD  3.5  WATT  LAMP 


VOLT.XGE 

PKR  CENT,  or 

NORMAL. 

V r 

CANDLE- 

pqWER 

PER  CENT.  OE 

NORMAL. 

WATTS  PER 

CAN  DLE- 

POWER. 

LIFE 

PER  CENT.  OK 

NORMAL. 

OETERIORA- 
\ riON 
e’erVent,  of 

NO^AL. 

y 

^ a.) 

y,-.,. 

a.3() 

1*1 

a() 

a.  99 

hd 

91 

4.S.') 

lt;5 

9 a 

4.93 

1»4 

99 

4.44 

394 

23 

ha 

73 

4.29 

319  H 

32 

t»(; 

78 

4.99 

247 

44 

97 

S3 

3.93 

193 

31 

98 

SS 

— 3.7s 

1 33 

Of) 

99 

100 

94 

1 00 

3.64 

129 

loo 

79 

19(1 

191 

199 

3.3  s 

S4 

llS  

192 

111 

3.27 

(is 

14(i 

193 

1 19 

3.19 

3S 

173 

194 

123 

3.0a 

47 

211 

I9.i 

129 

2.9a 

39 

233 

199 

137 

2.8.3 

31 

319 

197 

143 

2.79 

29 

3S9 

198 

la2 

2.9S 

21 

474 

199 

la9 

2.99 

17 

373 

119 

197 

2.33 

19 

OH  7 • * 

These  tables  show  that  a 3%  increase  of  voltage  on 
the  lamp  nearly  halves  the  life,  while  6%  increase 
reduces  the  life  by  two-thirds. 

Irregular  pressure,  therefore,  necessarily  results  in 
the  use  of  lamps  in  which  the  power  cc  isumption  per 
candle  is  greater  than  a well  regulated  pressure  would 
allow.  The  result  is  reduced  capacity  of  station,  and 
reduced  station  efficiencv. 


GENERAL  ELECTRIC  COMPANY 


transtormer. 

THE  SAVING 
RESULTING 
FROM  GOOD 
REGULATION 


These  remarks  apply  with  special  force  to  alternat- 
ing current  stations,  since  we  have  here  two  sources  of 
possible  irregularity  in  voltage — the  generator  and  the 
Poor  regulation  is  most  apt  to  occur  in 
the  transformers,  and  the  utmost  care 
should  therefore  be  taken  in  their 
selection  and  use.  The  economy  of 
the  average  lamp  on  alternating 
systems  is  nearly  4 watts  per  candle. 
With  good  regulation  obtained  by  the  intelligent  use 
of  modern  transformers,  the  use  of  lamps  of  an  economy 
of  3.1  watts  per  candle  becomes  practicable.  It  is  thus 
possible  to  .save  25%  in  power  consumption  at  the  lamps 
and  increase  the  capacity  of  the  station  and  transformers 
by  the  same  amount. 

In  the  past  two  years  there  has  been  a marked 
advance  in  the  method  of  making  transformer  installa- 
tions. The  general  adoption  of  higher  voltage  second- 
aries gives  smaller  loss  in  wires  and  permits  the  use  of 
larger  transformer  units,  thus  greatly  improving  the 
regulation.  On  this  account  50  volt  lamps  are  gradually 
going  out  of  use.  The  replacement 
of  a number  of  small  transformers  by 
one  large  unit,  and  of  old,  inefficient 
transformers  by  modern  types,  has 
also  been  of  immense  advantage  to 


MODERN 

TRANS- 

FORMER 

PRACTICE 


stations.  A large  number  of  stations,  however,  still  retain 
these  old  transformers,  and  load  their  circuits  with  large 
numbers  of  small  units.  Such  stations  necessarily  suffer 
from  loss  of  power,  bad  regulation,  and  a generally  deteri- 
orated lighting  service.  Simply  as  a return  on  the  invest- 
ment, it  would  !«}•  all  such  stations  to  scrap  their  old  trans- 
formers and  replace  them  with  large  and  modern  units. 


92 


GENERAL  ELECTRIC  COMPANY 


Proper  care  in  the  selection  of  transformers  con- 
siders the  cpiality  and  the  size.  (Juality  is  the  essential 
consideration  and  shonld  have  jrreference  to  hrst  cost. 
.\o  make  of  transformer  should  be  permitted  on  a 
station's  circuit  that  does  not  maintain  its  voltag'e  well 
within  3%  from  full  load  to  no  loath  d'he  simple  rule 
re.yardiny  size  is  to  use  as  large  Imits  as  possible  and 
thus  reduce  the  number  of  units  as  far  as  the  distribu- 
tion of  service  permits,  h'very  alternating  station  should 
aim  to  so  improve  regulation  as  to  permit  the  satisfactory 
use  of  3.1  watt  lamps. 

Good  regulation  is  eminently  imjiortant  to  preserve 
the  average  life  and  light  of  the  lamps,  to  prevent  the 
increase  of  power  consumed  by  the  lamirs,  and  to  per- 
mit the  use  of  lamps  of  lower  power  con- 
sumption, so  that  both  the  efficiency  and 
capacity  of  the  station  may  be  increased. 

Constant  voltage  at  the  lamjis  can 
be  maintained  onlv  by  constant  use  of 
reliable,  portable  instruments.  No  switchboard  in- 
strument should  be  relied  on,  without  frequent 
checking  by  some  reliable  standard.  Owing  to 
the  varying  drop  at  different  loads,  constant  voltage  at 
the  station  is  not  what  is  wanted.  Pressure  readings 
should  be  taken  at  customers'  lamps  at  numerous  points, 
the  readings  being  made  at  times  of  ma.ximum,  average 
and  minimum  load.  Not  less  than  five  to  ten  readings 
should  be  matle  at  each  point  visited,  the  voltmeter  being 
left  in  circuit  for  four  or  five  minutes  and  readings  taken 


HOW  TO 
MAINTAIN 
CONSTANT 
PRESSURE 


every  fifteen  seconds.  The  average  of  all  the  readings 
gives  the  average  voltage  of  the  circuits.  Lamjrs  should 
be  ordered  for  this  voltage,  or  if  desired,  the  voltage  of 
the  circuits  can  be  reduced  or  increased  to  suit  the  lamps 


93 


INCANDESCENT  STREET  ILLUMINATION-CHICAGO 


GENERAL  ELECTRIC  COMPANY 


in  use.  'I'he  practical  points  are  to  determine  the  a\-er- 
age  volta^Lje  at  frequent  periotl.s  with  a portable  voltmeter 
at  various  points  of  the  circuits,  ami  then  to  arran^m 
the  voltag-e  of  the  lamps  ami  circuits  so  that  the\'  agree. 

THE  MEASURE  OF  A 
LAMP’S  VALUE 

()  determine  relative  values  of 
various  lamps,  a correct  basis  cjf 
comparison  must  be  established. 
Comparison  should  not  be  made 
solely  according  to  how  long 
lamps  will  burn,  since  the  candle- 
power  may  seriously  diminish. 

1 he  true  basis  of  compari- 
son, considering  both  life  and 
candle-power,  is  the  average  life 
of  the  lamps  measured  to  a speci- 
fied limit  of  candle-power  and 
called  the  useful  life  of  the  lamjx  According  to  this 
basis  of  comparison,  the  best  lamp,  other  conditions 
being  equal,  is  the  one  which  gives  the  longest  useful  life. 

Many  central  stations  today  consider  that  a lamp 
has  passed  its  useful  life  when  it  has  lost  20%  in  candle- 
power,  i.  c.,  when  it  has  dropped  to  80%  of  its  initial 
candle-power. 

Using  this  Soyo  limit,  we  have  a definite  basis  for 
the  determination  of  value  and  the  correct  comparison 
of  lamps. 

It  must  not  be  forgotten  that  for  this  method  of 
comparison  equal  conditions  are  essential. 


GENERAL  ELECTRIC  COMPANY 


The  practical  method  of  comparison  is  as  follows: — 
Lamps  of  similar  candle-power  and  voltage  are  burned  at 
the  same  initial  economy  (3.1  or  3.5  watts  per  candle)  on 
circuits  whose  voltage  is  maintained  exactly  normal.  At 
periods  of  50,  75  or  100  hours  the  lamps  are  removed 
from  the  circuits  and  candle-power  readings  taken,  the 
lamps  being  replaced  in  circuit  at  the  end  of  each  read- 
ing. Readings  are  thus  continued  until  the  candle- 
power  drops  to  80%  of  normal.  The  results  obtained 
are  then  plotted  in  curves,  and  the  periods  of  time  at  which 
the  average  curve  of  each  make  of  lamp  crosses  this  80% 
limit  of  candle-power  give  the  relative  \-alues. 


INCANDESCENT  LAMP  RENEWALS 

The  necessity  for  frequent  lamp  renewals  is  urgent 
on  all  systems  regardless  of  the  cost  of  power  and 
whether  lamp  renewals  are  charged  for  or  furnished  free. 

No  matter  how  well  constructed  or  ojierated  an 
electric  lighting  plant  may  be,  it  cannot  furnisb  clear, 
good  light  unless  the  circuits  be  periodically  swept  clean 
of  the  dim  lamps. 

This  cleaning  out  of  dim  laiujis  cannot  be  left  to  the 
customer.  To  be  thorough  and  effective,  lamp  renewals 
must  be  made  by  tbe  lighting  company  and  without 
charge.  Only  by  free  renewals  can  a station  have  that 
complete  control  of  its  lighting  service  which  is  requisite 


96 


GENERAL  ELECTRIC  COMPANY 


to  perfect  results.  'I'he  present  price  of  lamps  is  so  low  as 
to  make  it  possible  for  all  stations  to  furnish  free  renewals 
at  but  slirtht  e.xpense.  Free  renewals  could  be  profitably 
adopted  b\-  all  stations  instead  of  a reduction  of  rates. 

With  free  renewals,  one  of  the  following-  methods 
should  he  adopted: 

1.  Periodicalh’  remove  all  lamps  from  the  circuits  one 
to  four  times  per  \-ear,  according  to  conditions,  and 
rejdace  them  by  new  ones.  Photometer  the  lamps 
removed  and  save  those  measuring  above  a prescribed 
limit  (say  13  c.p.)  for  use  at  high  voltage  points,  or 
locations  where  reduced  candle-power  is  of  slight 
importance.  Scrap  the  remaining  lamps. 

2.  ('ii\-e  a new  lamjr  in  exchange  for  an  old  one  for,  sa}-, 
ever\-  S3. 00  worth  of  current  supplied,  or  fm-  any 
fi.xed  amount  determined  hv  the  meter  rates  and 
conditions. 

The  second  plan  is  an  excellent  one,  in  that  it  offers 
a bonus  for  the  use  of  current  and  regulates  renewals  on 
the  correct  basis  of  number  of  hours  of  lamp  ser\-ice.  It 
can  be  profitably  adopted  wherever  meters  are  in  use.  A 
station  attendant  should  visit  customers  C|uarterl)'  and 
install  the  number  of  new  lamps  due  each,  removing  and 
returning  to  the  station  an  equal  number  of  old  lamps. 
If  station  attendance  is  limited,  the  lighting  company  can 
fill  out  and  mail  to  their  customers,  each  quarter  year, 
blanks  similar  to  the  following. 


Office  of 

ELECTRIC  LIGHT  COMPANY 
Due  to  Mr. 


J90 


16  candle-power  lamps,  on  the  return  of  an  equal 
number  of  dim  lamps,  for  the  quarter  year  ending 
which  is  on  the  basis  of  one  lamp  for  every  $3.00  of  current  supplied. 
Present  this  Slip  at  the  Station,  or  Office. 


97 


GENERAL  ELECTRIC  COMPANY 


In  cases  where  lamps  must  be  charged  for,  some 
measures  should  be  adopted  to  induce  customers  to  renew 
their  dim  lamps:  as,  otherwise,  dim  lamps  will  be  con- 
tinued in  service  as  long  as  they  will  burn. 

A good  method  is  to  offer  new  lamps  in  exchange 
for  dim  ones  (not  burned  out)  at  a reduction  in  price  of 
one-quarter  or  one-half  cost.  A customer,  for  e.xample, 
would  save  b}'  jiaA'ing,  sa)',  half-price  for  the  renewal  of 
a dim  lamp,  instead  of  waiting  and  paying  full  price  when 
the  lamp  burns  out. 

Another  method  is  to  offer  lamps  for  renewals  at 
less  than  cost,  say  1 5 cents  each,  and  reserve  the  right 
to  sa}'  when  lamps  shall  be  renewed.  Such  a plan  works 
well,  as  no  customer  can  justly  complain  when  the 
company  renews  lamps  at  less  than  cost. 

The  price  of  lamps  to  the  customer  in  anv  case 
should  be  made  as  low  as  possible — cost  price  or  below 
cost — for  the  reason  that  profit  on  the  sale  of  lamps  is 
secondary  in  importance  to  the  sale  of  current  and 
improvement  in  quality  of  lighting  service.  High 
charges  and  illiberal  methods  in  sale  or  suj^pb'  of  lamps 
invariably  deteriorate  the  lighting  service  for  the 
following  reasons : 

1.  Customers  are  induced  to  purchase  cheap  lamps 
from  outside  parties,  and  therefore  use  a low  grade  of 
lamps. 

2.  Customers  tend  to  retain  lamps  in  ser\ice  as 
long  as  they  will  last,  and  thus  load  up  the  circuits  with 
numbers  of  old  and  dim  lamps. 

Every  station  should  have  some  system  of  lamp 
renewals,  which  will  not  depend  ujion  the  customer,  and 
which  will  limit  the  average  life  of  the  lanqis  to  within 
600  hours. 

9S 


GENERAL  ELECTRIC  COMPANY 


POINTS  TO  BE  REMEMBERED 

I'hat  a constant  in'cssiirc  at  tlie  lamps  must  he 
maintained. 

That  the  lamps  are  not  to  he  used  to  the  point  of 
breakage — the\'  should  he  renewed  when  the)'  hecome 
dim. 

That  satisfaction  to  customers,  and  the  success  of 
electric  lighting  is  dependent  upon  good,  full  and  clear 
light,  which  old,  hlack  and  dim  lamps  cannot  gi\'e. 

That  to  furnish  a good,  full  and  clear  light  is  as 
much  a part  of  the  Lighting  Compan)''s  business  as  to 
sujiph'  current  to  light  the  lamps. 

That  a compan\'  should  always  endeavor  to  keejithe 
average  life  of  lamps  within  600  hours. 

That  to  renew  tlim  lamps  jiroperlv  on  the  tree 
renewal  system,  inspectors  should  e.vamine  the  circuits 
regularly  when  the  lamps  are  burning.  If  lamp  renewals 
are  charged  to  customers,  induce  them  to  e.xchange  their 
dim  lamps. 

FAULTS  IN  INCANDESCENT  LAMPS 

RAPID  LOSS  OF  CANDLE-POWER 

Rapid  loss  of  candle-i^iower  is  a defect  in  incandescent 
lamps,  although  as  we  ha\'e  shown  all  lamps  suffer  a 
gradual  loss  of  candle-power  as  they  are  used.  A very 
rajud  loss  in  candle-power  is,  however,  a real  fault,  due  to 
inc.xperienced  manufacture,  or  use  at  excessive  x'oltage. 
The  remedy  is  to  purchase  only  lamps  of  standard 
reputation  produced  by  the  experienced  manufacturer 
and  to  maintain  the  pressure  at  normal  on  the  lamps.  The 
pressure  should  be  carefully  tested  with  accurate 
portable  instruments  at  the  lamp  sockets,  and  if  found 
high,  the  pressure  should  be  regulated  to  accord  with  the 


99 


< 


ILLUMINATION  OF  OMAHA  EXPOSITION  GROUNDS— GRAND  COURT,  EAST  END 


GENERAL  ELECTRIC  COMPANY 


voltage  of  lamps,  or  lamps  supiilied  to  accord  with  the 
jiressure. 

BLACKENING  OF  BULBS 


Another  defect  in  incandescent  lamps  is  the 
blackening  of  bulbs,  although  this  is  more  often  a 
supposed  defect  than  a real  one.  A lamj)  may 
lose  in  candle-power  and  show  but  little  black- 
ening, and  on  the  other  hand,  a lamp  may  get 
quite  black  and  lose  little  in  candle-power. 

Thus  a 50  \'olt  lamj)  which  has  a more  stable 
filament  than  the  no  volt  lamp  often  shows 
considerable  blackening  with  little  loss  of 
candle-power. 

Blackening  in  good  lamps  results  from 
either  high  pressure  or  e.xcessive  life.  This  is  a 
supposed  fault.  The  best  of  lamps,  if  burned 
too  long,  will  always  show  a certain  amount  of 
blackening.  The  remedies  are,  of  course,  reg- 
ulation of  pressure  and  frequent  renewals. 


The  above  are  the  most  important 
defects  to  be  found  in  incandescent  lamps. 


GENERAL  ILLUMINATION 

The  subject  of  illumination  has  been  divided  by 
Mr.  E.  L.  Elliott,  to  whom  we  are  indebted  for  many 
suggestions,  into  the  following  sub-divisions:  Intensity 
or  Brilliancy,  Distribution,  Diffusion  and  Quality. 

INTENSITY  OR  BRILLIANCY 
The  average  brilliancy  of  illumination  required  will 
depend  on  the  use  to  which  the  light  is  put.  “A  dim 
light  that  would  be  very  satisfactory  for  a church  would 
be' wholly  inadequate  for  a library  and  equally  unsuitable 
for  a ballroom.” 


lOI 


GENERAL  ELECTRIC  COMPANY 


The  illumination  t;-iven  by  one  candle  at  a distance 
of  one  foot  is  called  the  “candle-foot”  and  is  taken  as  a 
unit  of  intensity.  In  general,  intensity  of  illumination 
should  nowhere  be  less  than  one  candle-foot,  and  the 
demand  for  light  at  the  present  time  quite  frequently 
raises  the  brilliancy  to  double  this  amount.  As  the  inten- 
sity of  light  \'aries  inversely  with  the  square  of  the 
distance,  a i6  candle-power  lamp  gi\'es  a candle-foot  of 
light  at  a distance  of  four  feet.  A candle-foot  of  light 
is  a good  intensity  for  reading  purposes. 

Assuming  the  i6  candle-power  lamp  as  the  standard, 
it  is  generally  found  that  two  i6  candle-power  lamps  per 
100  square  feet  of  Hoor  space  give  good  illumination, 
three  very  bright,  and  four  brilliant.  These  general 
figures  will  be  modified  by  the  height  of  ceiling,  color  of 
walls  and  ceiling,  and  other  local  conditions.  The  lighting 
effect  is  reduced,  of  course,  b}'  an  increased  height  of 
ceiling.  A room  with  dark  walls  requires  nearly  three 
times  as  manv  lights  for  the  same  illumination  as  a room 
with  walls  painted  white.  With  the  amount  of  intense 
light  available  in  arc  and  incandescent  lighting,  there  is 
danger  ( f e.xceeding  “the  limits  of  effective  illumination 
and  producing  a glaring  intensity,”  which  should  be 
avoided  as  carefully  as  too  little  intensity  of  illumination. 

DISTRIBUTION  OF  LIGHT 

Distribution  considers  the  arrangement  of  the 
various  sources  of  light  and  the  determination  of  their 
candle-power.  The  object  should  be  to  “secure  a uniform 
brilliancy  on  a certain  jdane,  or  within  a given  space.  A 
room  uniformly  lighted,  even  though  comparati\'ely  dim, 
gives  an  effect  of  much  better  illumination  than  where 
there  is  great  brilliancy  at  some  points  and  comparative 


102 


GENERAL  ELECTRIC  COMPANY 


darkness  at  others.  Tlie  darker  parts,  e\'en  thoug-li 
actually  light  enough,  appear  dark  b)'  contrast,  while  the 
lighter  parts  are  dazzling.  For  this  reason  naked  lights 
of  any  kind  are  to  he  avoided,  since  they  must  appear  as 
dazzling  points,  in  contrast  with  the  general  illumination.” 


Dining  Room  of  the  Hotel  Marlboro,  New  York 

The  arrangement  of  the  lamps  is  dependent  very 
largely  upon  e.xisting  conditions.  In  factories  and  shops 
lamps  should  be  placed  o\’er  each  machine  or  bench  so 
as  to  give  the  necessary  light  for  each  workman.  In  the 
lighting  of  halls,  public  buildings  and  large  rooms, 
e.xcellent  effects  are  obtained  by  di\’iding  the  ceiling>'s 
into  squares  and  placing  a lamp  in  the  center  of  each 
square.  The  size  of  square  depends  on  the  height  of 
ceiling  and  the  intensity  of  illumination  desired. 
Another  excellent  method  consists  in  placing  the  lamjxs 
in  a border  along  the  walls  near  the  ceiling. 


GENERAL  ELECTRIC  COMPANY 


For  the  illumination  of  show  windows  and  display 
effects,  care  must  be  taken  to  illuminate  by  reflected 
light.  The  lamps  shcmld  be  so  jflaced  as  to  throw  their 
rays  upon  the  displa)’  without  casting  any  direct  rays 
on  the  observer. 

The  relati\'e  \-alue  of  high  candle-power  lamps  in 
case  of  an  equi\  alent  number  of  i6  candle-power  lamps 
is  worthy  of  notice.  Large  lamps  can  be  efflcientlv  used 
for  lighting  large  areas,  but  in  general,  a given  area  will 
be  much  less  effective!}'  lighted  by  high  candle-power 
lamps  than  an  equivalent  number  of  i6  candle-power 
lamps.  For  example,  sixteen  64  candle-power  lamps 
distributed  o\'er  a large  area  will  not  gi\'e  as  good  general 
illumination  as  sixty-four  16  candle-power  lamps  dis- 
tributed over  the  same  area.  1 1 igh  candle-power  lamps 
are  chiefly  useful  when  a brilliant  light  is  needed  at  one 
point,  or  where  space  is  limited  and  an  increase  in 
illuminating  effect  is  desired. 

DIFFUSION  OF  LIGHT 

“ Diffusion  refers  to  the  number  of  rays  that  cross 
each  point.  The  amount  of  diffusion  is  shown  by  the 
character  of  the  shadow.  Daylight  on  a cloudy  day  may 
he  considered  perfectl}-  diffused:  it  produces  no  shadows 
whatever.  The  light  from  the  electric  arc  is  least 
diffused,  since  it  emanates  from  a very  small  surface;  the 
shadows  cast  by  it  have  almost  perfectly  sharp  outlines. 
It  is  largelv  due  to  its  high  state  of  diffusion  that 
daylight,  though  vastly  more  intense  than  any  artificial 
illumination,  is  the  easiest  of  all  lights  on  the  eyes.  It 
is  a common  and  serious  mistake,  in  case  of  weak  or 
overstrained  eyes,  to  reduce  the  intensit}’  of  the  light, 
instead  of  increasing  the  diffusion." 


104 


GENERAL  ELECTRIC  COMPANY 


QUALITY  OF  LIGHT 

“Aside  from  difference  in  intensity,  light  produces 
many  different  effects  upon  the  optic  neryes  and  their 
centers  in  the  brain.  These  different  impressions  we 
ascribe  to  difference  in  the  quality  of  the  light.  Thus 
‘hard  light,’  ‘cold  light,’  ‘mellow  light,’  ‘ambient  light.’  etc., 
designate  yarious  qualities.  Ouality  in  light  is  e.xactly 
analogous  to  timbre  or  quality  in  sound,  which  is  likewise 
indepemlent  of  intensity.  The  most  obx'ious  differences  in 
quality  are  plainh'  those  called  color.  But  color  is  by  no 
means  the  onh'  element  of  quality.  The  proportion  of 
inyisible  rays  and  the  state  of  diffusion,  are  highly  impor- 
tant factors,  but  on  account  of  not  being  directly  yisible, 
they  ha\'e  been  generall}'  oyerlooked,  and  are  but  imper- 
fectly understood.” 

RELATIVE  VALUE  OF  ARC  AND 
INCANDESCENT  LIGHTING 

Arc  and  incandescent  lamps  hayeeach  their  separate 
fields  of  usefulness.  Incandescent  lamps  haye  the 
adyantage  that  they  can  be  distributed  so  as  to  ayoid  the 
shadows  necessarily  cast  by  one  single  source  of  light. 
For  large  rooms  with  space  not  seriously  obstructed  by 
pillars  or  machines,  arc  lamps,  especially  those  of  the 
enclosed  type,  haye  an  adyantage. 

A correctly  lighted  room  frequenth’  requires  both 
arc  and  incandescent  lights,  the  arc  for  general  illumina- 
tion and  the  incandescent  for  near  at  hand  lighting. 

A good  method  of  comparing  illuminating  yalues  is 
afforded  by  the  area  in  square  feet  a lamp  will  illuminate. 
One  1 6 candle-power  incandescent  lanqi  for  eyery  fifty 


GENERAL  ELECTRIC  COMPANY 


square  feet  of  floor  space  gives  good  illumination.  One  full 
450  watt  enclosed  arc  lamp  will  illuminate  an  area  of  600 
or  800  square  feet.  Nine  50  watt  16  candle-power  lamps, 
consuming  the  same  power  as  one  arc  will  illuminate  a 
little  more  than  half  the  area.  The  efificiency  of  arc 
lamps  on  this  basis  is,  therefore,  not  greater  than  two  to 
three  times  that  of  incandescent  lamps.  It  has  been 
found  that  unless  an  area  is  so  large  as  to  require 
200  to  300  incandescent  lights  distributed  over  it,  arc 
lamps  requiring  equal  total  power  will  not  light  tbe  area 
with  as  uniform  brilliancy. 


of 


THE  CORRECT  USE  OF  LIGHT 
HOW  TO  AVOID  HARMFUL  EFFECTS  ON  THE  EYES 
An  objection  frequently  urged 
against  the  incandescent  lamp  is  that 
it  is  harmful  to  the  eyes  and  ruins  the 
sight.  This  is  true  only  in  so  far  as 
the  lamp  ma)'  be  improjierh'  used. 
Any  form  of  light  as  frequently 
misused  would  produce  the  same 
harmful  results.  Few  people  think 
read  by  an  unshaded  oil  lamj), 


to 

will  sit  in  the  glare  of  a clear  glass 


attempting 
and  yet  many 
incandescent  lamp.  Incandescent  lamps  are  more 
generally  complained  of  because,  unlike  oil  or  gas,  they 
can  be  used  in  any  position.  Tookkeejiers  and  clerks 
are  often  seen  with  an  incandescent  lamp  at  the  end  of  a 
drop  hanging  directly  in  front  of  their  eyes — an 
impossible  jiosition  of  the  light  from  gas  or  oil. 

The  first  hygienic  consideration  in  artificial  lighting 
is  to  a\'oid  the  use  of  a single  bright  light  in  a poorly 
illuminated  room,  In  working  under  such'  a light,  the 


GENERAL  ELECTRIC  COMPANY 


eve  is  adapted  to  the  surroundino'  darkness  and  yet 
there  is  one  spot  in  the  middle  of  the  eye  that  is  kept 
constantly  fixed  on  the  very  bright  light.  The  brilliancy 
of  the  single  light  acting  on  the  eye  adjusted  to  darkness 
works  harm.  'I'here  should  be  a general  illumination  of 
the  room  in  addition  to  any  necessary  local  light.  If 
sufficient  general  illumination  is  jirovided,  the  eye  is 
adjusted  to  the  light,  and  the  local  light  can  be  safely 
used.  The  ideal  arrangement  provides  general  illumina- 
tion so  strong  that  a pencil  placed  on  the  page  of  a book 
casts  two  shadows  of  nearly  equal  intensity — one  coming 
from  the  general  light  and  the  other  from  the  local  light. 

Care  should  also  be  taken  to  prevent  direct  rays 
from  striking  the  eye.  The  light  that  reaches  the  eye 
by  day  is  always  reflected.  In  reading  or  writing,  to 
avoid  shadows,  the  light  should  come  over  the  left 
shoulder.  Only  the  reflected  rays  can  then  reach  the 
eye. 

Another  point  to  be  avoided  is  the  careless  general 
use  of  clear  glass,  unshaded  lamps.  Frosted  bulbs 
should  be  used  in  place  of  clear  glass  where  soft  light 
for  reading  is  required.  The  intensity  of  light  reflected 
from  a small  source  is  increased,  and  intense  light 
injures  the  eye.  With  a clear  glass  globe  the  whole 
volume  of  light  proceeds  directly  from  the  small  surface 
of  the  lamp  filament.  With  a frosted  bulb  the  light  is 
radiated  from  the  whole  surface  of  the  bulb  and  while 
the  total  illuminating  effect  is  practically  undiminished, 
the  light  is  softened  by  diffusion  to  the  great  comfort 
and  relief  of  the  eyes. 

Finally,  the  use  of  old,  dim,  and  blackened  lamps 
giving  but  a small  fraction  of  their  proper  light  is  very 
often  a source  of  trouble  in  not  supplying  a sufficient 


107 


GENERAL  ELECTRIC  COMPANY 


quantity  of  light.  Users  of  lamps  are  not  often 
aware  of  the  loss  in  candle-power  a lamp  undergoes 
and  so  it  happens  that  lamps  are  retained  in  use 
long  after  their  efficient  light-giving  power  has  vanished. 
Proper  attention  to  lamp  renewals  on  the  part  of  central 
stations  is  necessary  to  correct  this  evil. 

The  correct  use  of  light  requires  : 

That  there  should  be  general  illumination  in 
addition  to  the  light  near  at  hand. 

That  only  reflected  light  should  reach  the  eye.  The 
light  should  be  so  placed  as  to  throw  the  direct  rays  on 
the  book  or  work  and  not  in  the  eye. 

That  the  light  should  be  placed  so  that  shadows 
will  not  fall  on  the  work  in  hand. 

That  shades  and  frosted  bulbs  should  be  used  to 
soften  the  light. 

That  lamps  be  frequentl}’  renewed  to  keep  the 
light  up  to  full  candle-power. 


In  the  Dining  Room  of  the  Hotel  Savoy,  New  York 


r 


t 

t 

I 


Of 


INDEX 

THE  MANUFACTURE  OF  INCANDESCENT  LAMPS  ....  6 

THE  SELECTION  OF  LAMPS 12 

THE  PROPER  USE  OF  LAMPS J6 

STANDARD  50  VOLT  INCANDESCENT  LAMPS: 

4,  6,  8,  and  lO  CandIc-p>ower 22 

I 6,  20,  and  24  Candle-power  24 

32  Candle-power  . . . . . . 26 

50  Candle-power  . . . . . ,28 

100  and  J50  Candle-power  , , 30 

STANDARD  100  TO  125  VOLT  INCANDESCENT  LAMPS: 

4,  6,  8,  and  10  Candle-power 32 

1 6 Candle-power  34 

32  Candle-power  . . . . . . . . . . . , ,36 

50  Candle-power  38 

100  and  150  Candle-power  ..........  40 

Street  Railway  Lamp  ,,,. 41 

SPECIAL  INCANDESCENT  LAMPS : 

200  to  250  Volt  Lamps 46 

Round  Bulb  Lamps  . . . 48 

Tubular  Lamps  50 

Stcreopticon  Lamps  52 

Edison  Night  Lamp  54 

Resistance  Lamp  . . . . , .56 

MINIATURE  INCANDESCENT  LAMPS  AND  APPLIANCES: 

Candelabra  and  Decorative  Lamps  . . . . . . , . .61 

Regarding  Series  Lamps  . 63 

Series  Candelabra  Lamps  65 

Multiple  Candelabra  and  Sign  Lamps 67 

Special  Series  Lamps  . , .68 

Receptacles  and  Sockets  , 73 

Shades  for  Miniature  Lamps  ..........75 

Battery  Lamps  . . . .77 

Stick-pin  and  Watch-charm  Lamps 82 

Examination  Lamp  for  Storage  Battery  ........  83 

APPENDIX  OF  INFORMATION  ON  INCANDESCENT  LAMPS: 

Life  and  Candle-power  of  Lamps 86 

The  Importance  of  Good  Regulation  89 

The  Measure  of  a Lamp's  Value  95 

Incandescent  Lamp  Renewals  . . , . . . , . . .96 

Points  to  be  Remembered  99 

Faults  in  Incandescent  Lamps  . 99 

General  Illumination  . . . . . . , . , . . .101 

Relative  Value  of  Arc  and  Incandescent  Lighting 105 

The  Correct  Use  of  Light 106 


no 


I 


MAIN  LAMP  SALES  OFFICES.  HARRISON,  N.  J. 


GENERAL  ELECTRIC  COMPANY 


Sales  Offices  : 

BOSTON,  MASS.,  200  Summer  Street. 

NEW  YORK.  N.  Y.,  44  Broad  Street. 

Syracuse,  N.  Y.,  Sedgwick,  Andrews  & Kennedy  Big. 
Buffalo,  N.  Y.,  Ellicott  Square  Building. 
PHILADELPHIA,  PA.,  509  Arch  Street. 

Baltimore,  Md.,  227  E.  German  Street. 

Pittsburg,  Pa.,  502  Tradesmens  Bank  Building. 
ATLANTA,  GA.,  Equitable  Building. 

New  Orleans,  La.,  917  Hennen  Building. 
CINCINNATI,  OHIO,  420  West  Fourth  Street. 
Columbus,  Ohio,  14  North  High  Street.! 

Nashville,  Tenn.,  Room  73,  Cole  Building. 

CHICAGO,  ILL.,  Monadnock  Building, 

Detroit,  Mich.,  704  Chamber  of  Commerce  Big. 

St.  Louis,  Mo.,  Wainwright  Building. 

Dallas,  Texas,  Scollard  Building. 

Helena,  Mont.,  Electric  Building. 

Minneapolis,  Minn.,  PhoenixJBuilding. 

DENVER,  COLO.,  Kittredge  Building. 

Salt  Lake  City,  Utah,  Templeton  Building. 

SAN  FRANCISCO,  CAL.,  Claus  Spreckels  Building. 
Portland,  Ore.,  Worcester  Building. 

Los  Angeles,  Cal.,  Douglas  Building. 

For  aM  Business  outside  the  United  States  and 
Canada:  Foreign  Dept.,  Schenectady,  N.  Y., 
and  44  Broad  Street,  New  York, 


For  Canada,  address  Canadian  General  Electric 
Company,  Ltd.,  Toronto,  Ontario. 


Principal  Offices,  Schenectady,  N.  Y. 


MAIN  LAMP  SALES  OFFICES.  HARRISON.  N.  J. 


